Merge branch 'develop' into feature/recording_selector

db/manifest

@@ -246,4 +246,9 @@ text_message_migration.sql
 user_model_about_changes.sql
 performance_samples.sql
 user_presences.sql
-discard_scores_optimized.sql
+discard_scores_optimized.sql
+backing_tracks.sql
+metronome.sql
+recorded_backing_tracks.sql
+recorded_backing_tracks_add_filename.sql
+user_syncs_include_backing_tracks.sql

db/up/backing_tracks.sql

@@ -0,0 +1,2 @@
+ALTER TABLE active_music_sessions ADD COLUMN backing_track_path VARCHAR(1024);
+ALTER TABLE active_music_sessions ADD COLUMN backing_track_initiator_id VARCHAR(64);

db/up/metronome.sql

@@ -0,0 +1,2 @@
+ALTER TABLE active_music_sessions ADD COLUMN metronome_active BOOLEAN NOT NULL DEFAULT FALSE;
+ALTER TABLE active_music_sessions ADD COLUMN metronome_initiator_id VARCHAR(64);

db/up/recorded_backing_tracks.sql

@@ -0,0 +1,38 @@
+CREATE UNLOGGED TABLE backing_tracks (
+  id VARCHAR(64) NOT NULL PRIMARY KEY DEFAULT uuid_generate_v4(),
+  filename VARCHAR(1024) NOT NULL,
+
+  connection_id VARCHAR(64) NOT NULL REFERENCES connections(id) ON DELETE CASCADE,
+  client_track_id VARCHAR(64) NOT NULL,
+  client_resource_id VARCHAR(100),
+  
+  created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+  updated_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP  
+);
+
+CREATE TABLE recorded_backing_tracks (
+    id BIGINT PRIMARY KEY,
+    user_id VARCHAR(64) REFERENCES users(id) ON DELETE CASCADE,    
+    backing_track_id VARCHAR(64),
+    recording_id VARCHAR(64) NOT NULL,
+    
+    client_track_id VARCHAR(64) NOT NULL,
+    is_part_uploading BOOLEAN NOT NULL DEFAULT FALSE,
+    next_part_to_upload INTEGER NOT NULL DEFAULT 0,
+    upload_id CHARACTER VARYING(1024),
+    part_failures INTEGER NOT NULL DEFAULT 0,
+    discard BOOLEAN,
+    download_count INTEGER NOT NULL DEFAULT 0,
+    md5 CHARACTER VARYING(100),
+    length BIGINT,
+    client_id VARCHAR(64) NOT NULL,
+    file_offset BIGINT,
+
+    url VARCHAR(1024) NOT NULL,
+    fully_uploaded BOOLEAN NOT NULL DEFAULT FALSE,
+    upload_failures INTEGER NOT NULL DEFAULT 0,    
+    created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    updated_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP
+);
+
+ALTER TABLE recorded_backing_tracks ALTER COLUMN id SET DEFAULT nextval('tracks_next_tracker_seq');

db/up/recorded_backing_tracks_add_filename.sql

@@ -0,0 +1,2 @@
+ALTER TABLE recorded_backing_tracks ADD COLUMN filename VARCHAR NOT NULL;
+ALTER TABLE recorded_backing_tracks ADD COLUMN last_downloaded_at TIMESTAMP WITHOUT TIME ZONE;

db/up/user_syncs_include_backing_tracks.sql

@@ -0,0 +1,47 @@
+
+DROP VIEW user_syncs;
+
+CREATE VIEW user_syncs AS
+    SELECT  DISTINCT b.id AS recorded_track_id,
+            CAST(NULL as BIGINT) AS mix_id,
+            CAST(NULL as BIGINT) AS quick_mix_id,
+            CAST(NULL as BIGINT) AS recorded_backing_track_id,
+            b.id AS unified_id,
+            a.user_id AS user_id,
+            b.fully_uploaded,
+            recordings.created_at AS created_at,
+            recordings.id AS recording_id
+    FROM recorded_tracks a INNER JOIN recordings ON a.recording_id = recordings.id AND duration IS NOT NULL AND all_discarded = FALSE AND deleted = FALSE INNER JOIN recorded_tracks b ON a.recording_id = b.recording_id
+    UNION ALL
+    SELECT  CAST(NULL AS BIGINT) AS recorded_track_id,
+            CAST(NULL as BIGINT) AS mix_id,
+            CAST(NULL as BIGINT) AS quick_mix_id,
+            a.id AS recorded_backing_track_id,
+            a.id AS unified_id,
+            a.user_id AS user_id,
+            a.fully_uploaded,
+            recordings.created_at AS created_at,
+            recordings.id AS recording_id
+    FROM recorded_backing_tracks a INNER JOIN recordings ON a.recording_id = recordings.id AND duration IS NOT NULL AND all_discarded = FALSE AND deleted = FALSE
+    UNION ALL
+    SELECT  CAST(NULL as BIGINT) AS recorded_track_id,
+            mixes.id AS mix_id,
+            CAST(NULL as BIGINT) AS quick_mix_id,
+            CAST(NULL as BIGINT) AS recorded_backing_track_id,
+            mixes.id AS unified_id,
+            claimed_recordings.user_id AS user_id,
+            NULL as fully_uploaded,
+            recordings.created_at AS created_at,
+            recordings.id AS recording_id
+    FROM mixes INNER JOIN recordings ON mixes.recording_id = recordings.id INNER JOIN claimed_recordings ON recordings.id = claimed_recordings.recording_id WHERE claimed_recordings.discarded = FALSE AND deleted = FALSE
+    UNION ALL
+    SELECT  CAST(NULL as BIGINT) AS recorded_track_id,
+            CAST(NULL as BIGINT) AS mix_id,
+            quick_mixes.id AS quick_mix_id,
+            CAST(NULL as BIGINT) AS recorded_backing_track_id,
+            quick_mixes.id AS unified_id,
+            quick_mixes.user_id,
+            quick_mixes.fully_uploaded,
+            recordings.created_at AS created_at,
+            recordings.id AS recording_id
+    FROM quick_mixes INNER JOIN recordings ON quick_mixes.recording_id = recordings.id AND duration IS NOT NULL AND all_discarded = FALSE AND deleted = FALSE;

monitor/spec/support/utilities.rb

@@ -430,7 +430,7 @@ def assert_all_tracks_seen(users=[])
   users.each do |user|
     in_client(user) do
       users.reject {|u| u==user}.each do |other|
-        find('div.track-label',  text: other.name)
+        find('div.track-label > span',  text: other.name)
         #puts user.name + " is able to see " + other.name + "\'s track"
       end
     end

ruby/lib/jam_ruby.rb

@@ -87,6 +87,7 @@ require "jam_ruby/lib/stats.rb"
 require "jam_ruby/amqp/amqp_connection_manager"
 require "jam_ruby/database"
 require "jam_ruby/message_factory"
+require "jam_ruby/models/backing_track"
 require "jam_ruby/models/feedback"
 require "jam_ruby/models/feedback_observer"
 #require "jam_ruby/models/max_mind_geo"
@@ -132,8 +133,11 @@ require "jam_ruby/models/search"
 require "jam_ruby/models/recording"
 require "jam_ruby/models/recording_comment"
 require "jam_ruby/models/recording_liker"
+require "jam_ruby/models/recorded_backing_track"
+require "jam_ruby/models/recorded_backing_track_observer"
 require "jam_ruby/models/recorded_track"
 require "jam_ruby/models/recorded_track_observer"
+require "jam_ruby/models/recorded_video"
 require "jam_ruby/models/quick_mix"
 require "jam_ruby/models/quick_mix_observer"
 require "jam_ruby/models/share_token"
@@ -197,7 +201,6 @@ require "jam_ruby/models/score_history"
 require "jam_ruby/models/jam_company"
 require "jam_ruby/models/user_sync"
 require "jam_ruby/models/video_source"
-require "jam_ruby/models/recorded_video"
 require "jam_ruby/models/text_message"
 require "jam_ruby/jam_tracks_manager"
 

ruby/lib/jam_ruby/constants/validation_messages.rb

@@ -82,6 +82,8 @@ module ValidationMessages
   MUST_BE_KNOWN_TIMEZONE = "not valid"
   JAM_TRACK_ALREADY_OPEN = 'another jam track already open'
   RECORDING_ALREADY_IN_PROGRESS = "recording being made"
+  METRONOME_ALREADY_OPEN = 'another metronome already open'
+  BACKING_TRACK_ALREADY_OPEN = 'another audio file already open'
 
   # notification
   DIFFERENT_SOURCE_TARGET = 'can\'t be same as the sender'

ruby/lib/jam_ruby/models/active_music_session.rb

@@ -7,7 +7,7 @@ module JamRuby
 
     self.table_name = 'active_music_sessions'
 
-    attr_accessor :legal_terms, :max_score, :opening_jam_track, :opening_recording
+    attr_accessor :legal_terms, :max_score, :opening_jam_track, :opening_recording, :opening_backing_track, :opening_metronome
 
     belongs_to :claimed_recording, :class_name => "JamRuby::ClaimedRecording", :foreign_key => "claimed_recording_id", :inverse_of => :playing_sessions
     belongs_to :claimed_recording_initiator, :class_name => "JamRuby::User", :inverse_of => :playing_claimed_recordings, :foreign_key => "claimed_recording_initiator_id"
@@ -15,6 +15,9 @@ module JamRuby
     belongs_to :jam_track, :class_name => "JamRuby::JamTrack", :foreign_key => "jam_track_id", :inverse_of => :playing_sessions
     belongs_to :jam_track_initiator, :class_name => "JamRuby::User", :inverse_of => :playing_jam_tracks, :foreign_key => "jam_track_initiator_id"
 
+    belongs_to :backing_track_initiator, :class_name => "JamRuby::User", :inverse_of => :playing_jam_tracks, :foreign_key => "backing_track_initiator_id"
+    belongs_to :metronome_initiator, :class_name => "JamRuby::User", :inverse_of => :playing_jam_tracks, :foreign_key => "metronome_initiator_id"
+
     has_one :music_session, :class_name => "JamRuby::MusicSession", :foreign_key => 'music_session_id'
     has_one :mount, :class_name => "JamRuby::IcecastMount", :inverse_of => :music_session, :foreign_key => 'music_session_id'
     belongs_to :creator, :class_name => 'JamRuby::User', :foreign_key => :user_id
@@ -27,6 +30,8 @@ module JamRuby
     validate :creator_is_musician
     validate :validate_opening_recording, :if => :opening_recording
     validate :validate_opening_jam_track, :if => :opening_jam_track
+    validate :validate_opening_backing_track, :if => :opening_backing_track
+    validate :validate_opening_metronome, :if => :opening_metronome
 
     after_create :started_session
 
@@ -73,22 +78,52 @@ module JamRuby
       if is_jam_track_open?
         errors.add(:claimed_recording, ValidationMessages::JAM_TRACK_ALREADY_OPEN)
       end
+
+      if is_backing_track_open?
+        errors.add(:claimed_recording, ValidationMessages::BACKING_TRACK_ALREADY_OPEN)
+      end
+
+      if is_metronome_open?
+        errors.add(:claimed_recording, ValidationMessages::METRONOME_ALREADY_OPEN)
+      end
     end
 
     def validate_opening_jam_track
+      validate_other_audio(:jam_track)      
+    end
+
+    def validate_opening_backing_track
+      validate_other_audio(:backing_track)
+    end
+
+    def validate_opening_metronome
+      validate_other_audio(:metronome)
+    end
+
+    def validate_other_audio(error_key)
+      # validate that there is no metronome already open in this session
+      if metronome_active_was
+        errors.add(error_key, ValidationMessages::METRONOME_ALREADY_OPEN)
+      end
+
+      # validate that there is no backing track already open in this session
+      if backing_track_path_was.present?
+        errors.add(error_key, ValidationMessages::BACKING_TRACK_ALREADY_OPEN)
+      end
+
       # validate that there is no jam track already open in this session
-      unless jam_track_id_was.nil?
-        errors.add(:jam_track, ValidationMessages::JAM_TRACK_ALREADY_OPEN)
+      if jam_track_id_was.present?
+        errors.add(error_key, ValidationMessages::JAM_TRACK_ALREADY_OPEN)
       end
 
       # validate that there is no recording being made
       if is_recording?
-        errors.add(:jam_track, ValidationMessages::RECORDING_ALREADY_IN_PROGRESS)
+        errors.add(error_key, ValidationMessages::RECORDING_ALREADY_IN_PROGRESS)
       end
 
       # validate that there is no recording being played back to the session
       if is_playing_recording?
-        errors.add(:jam_track, ValidationMessages::CLAIMED_RECORDING_ALREADY_IN_PROGRESS)
+        errors.add(error_key, ValidationMessages::CLAIMED_RECORDING_ALREADY_IN_PROGRESS)
       end
     end
 
@@ -593,6 +628,14 @@ module JamRuby
       !self.jam_track.nil?
     end
 
+    def is_backing_track_open?
+      self.backing_track_path.present?
+    end
+
+    def is_metronome_open?
+      self.metronome_active.present?
+    end
+
     # is this music session currently recording?
     def is_recording?
       recordings.where(:duration => nil).count > 0
@@ -742,6 +785,35 @@ module JamRuby
       self.save
     end
 
+    # @param backing_track_path is a relative path:
+    def open_backing_track(user, backing_track_path)
+      self.backing_track_path = backing_track_path
+      self.backing_track_initiator = user
+      self.opening_backing_track = true
+      self.save
+      self.opening_backing_track = false
+    end
+
+    def close_backing_track
+      self.backing_track_path = nil
+      self.backing_track_initiator = nil
+      self.save
+    end
+
+    def open_metronome(user)
+      self.metronome_active = true
+      self.metronome_initiator = user
+      self.opening_metronome = true
+      self.save
+      self.opening_metronome = false
+    end
+
+    def close_metronome
+      self.metronome_active = false
+      self.metronome_initiator = nil
+      self.save
+    end
+
     def self.sync(session_history)
       music_session = MusicSession.find_by_id(session_history.id)
 

ruby/lib/jam_ruby/models/backing_track.rb

@@ -0,0 +1,21 @@
+module JamRuby
+  class BackingTrack < ActiveRecord::Base
+
+    self.table_name = "backing_tracks"
+    self.primary_key = 'id'
+
+    default_scope order('created_at ASC')
+
+    belongs_to :connection, :class_name => "JamRuby::Connection", :inverse_of => :tracks, :foreign_key => 'connection_id'
+    validates :connection, presence: true
+    validates :client_track_id, presence: true
+    validates :filename, presence: true
+
+    def user
+      self.connection.user
+    end
+
+    
+
+  end
+end

ruby/lib/jam_ruby/models/connection.rb

@@ -18,6 +18,7 @@ module JamRuby
     belongs_to :music_session, :class_name => "JamRuby::ActiveMusicSession", foreign_key: :music_session_id
     has_one :latency_tester, class_name: 'JamRuby::LatencyTester', foreign_key: :client_id, primary_key: :client_id
     has_many :tracks, :class_name => "JamRuby::Track", :inverse_of => :connection, :foreign_key => 'connection_id', :dependent => :delete_all
+    has_many :backing_tracks, :class_name => "JamRuby::BackingTrack", :inverse_of => :connection, :foreign_key => 'connection_id', :dependent => :delete_all
     has_many :video_sources, :class_name => "JamRuby::VideoSource", :inverse_of => :connection, :foreign_key => 'connection_id', :dependent => :delete_all
 
     validates :as_musician, :inclusion => {:in => [true, false, nil]}

ruby/lib/jam_ruby/models/mix.rb

@@ -138,11 +138,17 @@ module JamRuby
 
       manifest = { "files" => [], "timeline" => [] }
       mix_params = []
+
       recording.recorded_tracks.each do |recorded_track|
         manifest["files"] << { "filename" => recorded_track.sign_url(one_day), "codec" => "vorbis", "offset" => 0 }
         mix_params << { "level" => 100, "balance" => 0 }
       end
 
+      recording.recorded_backing_tracks.each do |recorded_backing_track|
+        manifest["files"] << { "filename" => recorded_backing_track.sign_url(one_day), "codec" => "vorbis", "offset" => 0 }
+        mix_params << { "level" => 100, "balance" => 0 }
+      end
+
       manifest["timeline"] << { "timestamp" => 0, "mix" => mix_params }
       manifest["output"] = { "codec" => "vorbis" }
       manifest["recording_id"] = self.recording.id

ruby/lib/jam_ruby/models/recorded_backing_track.rb

@@ -0,0 +1,196 @@
+module JamRuby
+  # BackingTrack analog to JamRuby::RecordedTrack
+  class RecordedBackingTrack < ActiveRecord::Base
+
+    include JamRuby::S3ManagerMixin
+
+    attr_accessor   :marking_complete
+    attr_writer :current_user
+
+    belongs_to :user, :class_name => "JamRuby::User", :inverse_of => :recorded_backing_tracks
+    belongs_to :recording, :class_name => "JamRuby::Recording", :inverse_of => :recorded_backing_tracks
+    validates :filename, :presence => true
+
+    validates :client_id, :presence => true  # not a connection relation on purpose
+    validates :backing_track_id, :presence => true # not a track relation on purpose
+    validates :client_track_id, :presence => true
+    validates :md5, :presence => true, :if => :upload_starting?
+    validates :length, length: {minimum: 1, maximum: 1024 * 1024 * 256 }, if: :upload_starting?  # 256 megs max. is this reasonable? surely...
+    validates :user, presence: true
+    validates :download_count, presence: true
+
+    before_destroy :delete_s3_files
+    validate :validate_fully_uploaded
+    validate :validate_part_complete
+    validate :validate_too_many_upload_failures
+    validate :verify_download_count
+
+    def self.create_from_backing_track(backing_track, recording) 
+      recorded_backing_track = self.new
+      recorded_backing_track.recording = recording
+      recorded_backing_track.client_id = backing_track.connection.client_id
+      recorded_backing_track.backing_track_id = backing_track.id
+      recorded_backing_track.client_track_id = backing_track.client_track_id
+      recorded_backing_track.user = backing_track.connection.user
+      recorded_backing_track.filename = backing_track.filename
+      recorded_backing_track.next_part_to_upload = 0
+      recorded_backing_track.file_offset = 0
+      recorded_backing_track[:url] = construct_filename(recording.created_at, recording.id, backing_track.client_track_id)
+      recorded_backing_track.save
+      recorded_backing_track
+    end
+
+    def sign_url(expiration_time = 120)
+      s3_manager.sign_url(self[:url], {:expires => expiration_time, :response_content_type => 'audio/ogg', :secure => false})
+    end
+
+    def can_download?(some_user)
+      claimed_recording = recording.claimed_recordings.find{|claimed_recording| claimed_recording.user == some_user }
+
+      if claimed_recording
+        !claimed_recording.discarded
+      else
+        false
+      end
+    end
+
+    def too_many_upload_failures?
+      upload_failures >= APP_CONFIG.max_track_upload_failures
+    end
+
+    def too_many_downloads?
+      (self.download_count < 0 || self.download_count > APP_CONFIG.max_audio_downloads) && !@current_user.admin
+    end
+
+    def upload_starting?
+      next_part_to_upload_was == 0 && next_part_to_upload == 1
+    end
+
+    def validate_too_many_upload_failures
+      if upload_failures >= APP_CONFIG.max_track_upload_failures
+        errors.add(:upload_failures, ValidationMessages::UPLOAD_FAILURES_EXCEEDED)
+      end
+    end
+
+    def validate_fully_uploaded
+      if marking_complete && fully_uploaded && fully_uploaded_was
+        errors.add(:fully_uploaded, ValidationMessages::ALREADY_UPLOADED)
+      end
+    end
+
+    def validate_part_complete
+
+      # if we see a transition from is_part_uploading from true to false, we validate
+      if is_part_uploading_was && !is_part_uploading
+        if next_part_to_upload_was + 1 != next_part_to_upload
+          errors.add(:next_part_to_upload, ValidationMessages::INVALID_PART_NUMBER_SPECIFIED)
+        end
+
+        if file_offset > length
+          errors.add(:file_offset, ValidationMessages::FILE_OFFSET_EXCEEDS_LENGTH)
+        end
+      elsif next_part_to_upload_was + 1 == next_part_to_upload
+        # this makes sure we are only catching 'upload_part_complete' transitions, and not upload_start
+        if next_part_to_upload_was != 0
+          # we see that the part number was ticked--but was is_part_upload set to true before this transition?
+          if !is_part_uploading_was && !is_part_uploading
+            errors.add(:next_part_to_upload, ValidationMessages::PART_NOT_STARTED)
+          end
+        end
+      end
+    end
+
+    def verify_download_count
+      if (self.download_count < 0 || self.download_count > APP_CONFIG.max_audio_downloads) && !@current_user.admin
+        errors.add(:download_count, "must be less than or equal to 100")
+      end
+    end
+
+
+    def upload_start(length, md5)
+      #self.upload_id set by the observer
+      self.next_part_to_upload = 1
+      self.length = length
+      self.md5 = md5
+      save
+    end
+
+    # if for some reason the server thinks the client can't carry on with the upload,
+    # this resets everything to the initial state
+    def reset_upload
+      self.upload_failures = self.upload_failures + 1
+      self.part_failures = 0
+      self.file_offset = 0
+      self.next_part_to_upload = 0
+      self.upload_id = nil
+      self.md5 = nil
+      self.length = 0
+      self.fully_uploaded = false
+      self.is_part_uploading = false
+      save :validate => false # skip validation because we need this to always work
+    end
+
+    def upload_next_part(length, md5)
+      self.marking_complete = true
+      if next_part_to_upload == 0
+        upload_start(length, md5)
+      end
+      self.is_part_uploading = true
+      save
+    end
+
+    def upload_sign(content_md5)
+      s3_manager.upload_sign(self[:url], content_md5, next_part_to_upload, upload_id)
+    end
+
+    def upload_part_complete(part, offset)
+      # validated by :validate_part_complete
+      self.marking_complete = true
+      self.is_part_uploading = false
+      self.next_part_to_upload = self.next_part_to_upload + 1
+      self.file_offset = offset.to_i
+      self.part_failures = 0
+      save
+    end
+
+    def upload_complete
+      # validate from happening twice by :validate_fully_uploaded
+      self.fully_uploaded = true
+      self.marking_complete = true
+      save
+    end
+
+    def increment_part_failures(part_failure_before_error)
+      self.part_failures = part_failure_before_error + 1
+      RecordedBackingTrack.update_all("part_failures = #{self.part_failures}", "id = '#{self.id}'")
+    end
+
+    def stored_filename
+      # construct a path from s3
+      RecordedBacknigTrack.construct_filename(recording.created_at, self.recording.id, self.client_track_id)
+    end
+
+    def update_download_count(count=1)
+      self.download_count = self.download_count + count
+      self.last_downloaded_at = Time.now
+    end
+
+    def delete_s3_files
+      s3_manager.delete(self[:url]) if self[:url] && s3_manager.exists?(self[:url])
+    end
+
+    def mark_silent
+      destroy
+
+      # check if we have all the files we need, now that the recorded_backing_track is out of the way
+      recording.preconditions_for_mix?
+    end
+
+    private
+
+    def self.construct_filename(created_at, recording_id, client_track_id)
+      raise "unknown ID" unless client_track_id
+      "recordings/#{created_at.strftime('%m-%d-%Y')}/#{recording_id}/backing-track-#{client_track_id}.ogg"
+    end
+  end  
+end

ruby/lib/jam_ruby/models/recorded_backing_track_observer.rb

@@ -0,0 +1,91 @@
+module JamRuby
+  class RecordedBackingTrackObserver < ActiveRecord::Observer
+
+    # if you change the this class, tests really should accompany.  having alot of logic in observers is really tricky, as we do here
+    observe JamRuby::RecordedBackingTrack
+
+    def before_validation(recorded_backing_tracks)
+
+      # if we see that a part was just uploaded entirely, validate that we can find the part that was just uploaded
+      if recorded_backing_tracks.is_part_uploading_was && !recorded_backing_tracks.is_part_uploading
+        begin
+          aws_part = recorded_backing_tracks.s3_manager.multiple_upload_find_part(recorded_backing_tracks[:url], recorded_backing_tracks.upload_id, recorded_backing_tracks.next_part_to_upload - 1)
+          # calling size on a part that does not exist will throw an exception... that's what we want
+          aws_part.size
+        rescue SocketError => e
+          raise # this should cause a 500 error, which is what we want.  The client will retry later on 500.
+        rescue Exception => e
+          recorded_backing_tracks.errors.add(:next_part_to_upload, ValidationMessages::PART_NOT_FOUND_IN_AWS)
+        rescue RuntimeError => e
+          recorded_backing_tracks.errors.add(:next_part_to_upload, ValidationMessages::PART_NOT_FOUND_IN_AWS)
+        rescue
+          recorded_backing_tracks.errors.add(:next_part_to_upload, ValidationMessages::PART_NOT_FOUND_IN_AWS)
+        end
+
+      end
+
+      # if we detect that this just became fully uploaded -- if so, tell s3 to put the parts together
+      if recorded_backing_tracks.marking_complete && !recorded_backing_tracks.fully_uploaded_was && recorded_backing_tracks.fully_uploaded
+
+        multipart_success = false
+        begin
+          recorded_backing_tracks.s3_manager.multipart_upload_complete(recorded_backing_tracks[:url], recorded_backing_tracks.upload_id)
+          multipart_success = true
+        rescue SocketError => e
+          raise # this should cause a 500 error, which is what we want.  The client will retry later.
+        rescue Exception => e
+            #recorded_track.reload
+            recorded_backing_tracks.reset_upload
+            recorded_backing_tracks.errors.add(:upload_id, ValidationMessages::BAD_UPLOAD)
+        end
+
+        # unlike RecordedTracks, only the person who uploaded can download it, so no need to notify
+
+        # tell all users that a download is available, except for the user who just uploaded
+        # recorded_backing_tracks.recording.users.each do |user|
+          #Notification.send_download_available(recorded_backing_tracks.user_id) unless user == recorded_backing_tracks.user
+        # end
+
+      end
+    end
+
+    def after_commit(recorded_backing_track)
+
+    end
+
+    # here we tick upload failure counts, or revert the state of the model, as needed
+    def after_rollback(recorded_backing_track)
+      # if fully uploaded, don't increment failures
+      if recorded_backing_track.fully_uploaded
+        return
+      end
+
+      # increment part failures if there is a part currently being uploaded
+      if recorded_backing_track.is_part_uploading_was
+       #recorded_track.reload # we don't want anything else that the user set to get applied
+        recorded_backing_track.increment_part_failures(recorded_backing_track.part_failures_was)
+        if recorded_backing_track.part_failures >= APP_CONFIG.max_track_part_upload_failures
+          # save upload id before we abort this bad boy
+          upload_id = recorded_backing_track.upload_id
+          begin
+            recorded_backing_track.s3_manager.multipart_upload_abort(recorded_backing_track[:url], upload_id)
+          rescue => e
+            puts e.inspect
+          end
+          recorded_backing_track.reset_upload
+          if recorded_backing_track.upload_failures >= APP_CONFIG.max_track_upload_failures
+            # do anything?
+          end
+        end
+      end
+
+    end
+
+    def before_save(recorded_backing_track)
+      # if we are on the 1st part, then we need to make sure we can save the upload_id
+      if recorded_backing_track.next_part_to_upload == 1
+        recorded_backing_track.upload_id = recorded_backing_track.s3_manager.multipart_upload_start(recorded_backing_track[:url])
+      end
+    end
+  end
+end

ruby/lib/jam_ruby/models/recording.rb

@@ -11,6 +11,7 @@ module JamRuby
     has_many :quick_mixes, :class_name => "JamRuby::QuickMix", :foreign_key => :recording_id, :dependent => :destroy
     has_many :recorded_tracks, :class_name => "JamRuby::RecordedTrack", :foreign_key => :recording_id, :dependent => :destroy
     has_many :recorded_videos, :class_name => "JamRuby::RecordedVideo", :foreign_key => :recording_id, :dependent => :destroy
+    has_many :recorded_backing_tracks, :class_name => "JamRuby::RecordedBackingTrack", :foreign_key => :recording_id, :dependent => :destroy
     has_many :comments, :class_name => "JamRuby::RecordingComment", :foreign_key => "recording_id", :dependent => :destroy
     has_many :likes, :class_name => "JamRuby::RecordingLiker", :foreign_key => "recording_id", :dependent => :destroy
     has_many :plays, :class_name => "JamRuby::PlayablePlay", :as => :playable, :dependent => :destroy
@@ -179,6 +180,14 @@ module JamRuby
       recorded_tracks.where(:user_id => user.id)
     end
 
+    def recorded_backing_tracks_for_user(user)
+      unless self.users.exists?(user)
+        raise PermissionError, "user was not in this session"
+      end
+      recorded_backing_tracks.where(:user_id => user.id)
+    end
+
+
     def has_access?(user)
       users.exists?(user)
     end
@@ -209,6 +218,10 @@ module JamRuby
             connection.video_sources.each do |video|
               recording.recorded_videos << RecordedVideo.create_from_video_source(video, recording)
             end
+
+            connection.backing_tracks.each do |backing_track|
+              recording.recorded_backing_tracks << RecordedBackingTrack.create_from_backing_track(backing_track, recording)
+            end
           end
         end
       end
@@ -321,8 +334,7 @@ module JamRuby
               }
           )
       end
-
-      latest_recorded_track = downloads[-1][:next] if downloads.length > 0
+      latest_recorded_track = (downloads.length > 0) ? downloads[-1][:next] : 0
 
       Mix.joins(:recording).joins(:recording => :claimed_recordings)
       .order('mixes.id')
@@ -345,16 +357,31 @@ module JamRuby
             }
         )
       end
+      latest_mix = (downloads.length > 0) ? downloads[-1][:next] : 0
 
-      latest_mix = downloads[-1][:next] if downloads.length > 0
-
-      if !latest_mix.nil? && !latest_recorded_track.nil?
-        next_date = [latest_mix, latest_recorded_track].max
-      elsif latest_mix.nil?
-        next_date = latest_recorded_track
-      else
-        next_date = latest_mix
+      RecordedBackingTrack.joins(:recording).joins(:recording => :claimed_recordings)
+      .order('recorded_backing_tracks.id')
+      .where('recorded_backing_tracks.fully_uploaded = TRUE')
+      .where('recorded_backing_tracks.id > ?', since)
+      .where('recorded_backing_tracks.user_id = ?', user.id) # only the person who opened the backing track can have it back
+      .where('all_discarded = false')
+      .where('deleted = false')
+      .where('claimed_recordings.user_id = ? AND claimed_recordings.discarded = FALSE', user).limit(limit).each do |recorded_backing_track|
+          downloads.push(
+              {
+                  :type => "recorded_backing_track",
+                  :id => recorded_backing_track.client_track_id,
+                  :recording_id => recorded_backing_track.recording_id,
+                  :length => recorded_backing_track.length,
+                  :md5 => recorded_backing_track.md5,
+                  :url => recorded_backing_track[:url],
+                  :next => recorded_backing_track.id
+              }
+          )
       end
+      latest_recorded_backing_track = (downloads.length > 0) ? downloads[-1][:next] : 0
+
+      next_date = [latest_mix, latest_recorded_track, latest_recorded_backing_track].max
 
       if next_date.nil?
         next_date = since # echo back to the client the same value they passed in, if there are no results
@@ -417,6 +444,20 @@ module JamRuby
           Arel::Nodes::As.new('stream_mix', Arel.sql('item_type'))
       ]).reorder("")
 
+      # Select fields for quick mix. Note that it must include
+      # the same number of fields as the track or video in order for
+      # the union to work:
+      backing_track_arel = RecordedBackingTrack.select([
+          :id,
+          :recording_id,
+          :user_id,
+          :url,
+          :fully_uploaded,
+          :upload_failures,
+          :client_track_id,
+          Arel::Nodes::As.new('backing_track', Arel.sql('item_type'))
+      ]).reorder("")
+
       # Glue them together:
       union = track_arel.union(vid_arel)
 
@@ -439,7 +480,25 @@ module JamRuby
                          ])
 
       # And repeat:
-      union_all = arel.union(quick_mix_arel)
+      union_quick = arel.union(quick_mix_arel)
+      utable_quick = Arel::Nodes::TableAlias.new(union_quick, :recorded_items_quick)
+      arel = arel.from(utable_quick)
+
+      arel = arel.except(:select)
+      arel = arel.select([
+                             "recorded_items_quick.id",
+                             :recording_id,
+                             :user_id,
+                             :url,
+                             :fully_uploaded,
+                             :upload_failures,
+                             :client_track_id,
+                             :item_type
+                         ])
+
+
+      # And repeat for backing track:
+      union_all = arel.union(backing_track_arel)
       utable_all = Arel::Nodes::TableAlias.new(union_all, :recorded_items_all)
       arel = arel.from(utable_all)
 
@@ -455,7 +514,6 @@ module JamRuby
                              :item_type
                          ])
 
-
       # Further joining and criteria for the unioned object:
       arel = arel.joins("INNER JOIN recordings ON recordings.id=recorded_items_all.recording_id") \
         .where('recorded_items_all.user_id' => user.id) \
@@ -492,6 +550,13 @@ module JamRuby
             :recording_id => recorded_item.recording_id,
             :next => recorded_item.id
           })
+        elsif recorded_item.item_type == 'backing_track'
+          uploads << ({
+            :type => "recorded_backing_track",
+            :recording_id => recorded_item.recording_id,
+            :client_track_id => recorded_item.client_track_id,
+            :next => recorded_item.id
+          })        
         else
 
         end
@@ -513,6 +578,11 @@ module JamRuby
       recorded_tracks.each do |recorded_track|
         return false unless recorded_track.fully_uploaded
       end
+
+      recorded_backing_tracks.each do |recorded_backing_track|
+        return false unless recorded_backing_track.fully_uploaded
+      end
+
       true
     end
 

ruby/lib/jam_ruby/models/track.rb

@@ -55,11 +55,64 @@ module JamRuby
       return query
     end
 
+    def self.diff_track(track_class, existing_tracks, new_tracks, &blk)
+      result = []
+      if new_tracks.length == 0
+        existing_tracks.delete_all
+      else
+
+        # we will prune from this as we find matching tracks
+        to_delete = Set.new(existing_tracks)
+        to_add = Array.new(new_tracks)
+
+        existing_tracks.each do |existing_track|
+          new_tracks.each do |new_track|
+
+            if new_track[:id] == existing_track.id || new_track[:client_track_id] == existing_track.client_track_id
+              to_delete.delete(existing_track)
+              to_add.delete(new_track)
+
+              blk.call(existing_track, new_track)
+
+              result.push(existing_track)
+
+              if existing_track.save
+                next
+              else
+                result = existing_track
+                raise ActiveRecord::Rollback
+              end
+            end
+          end
+        end
+
+
+        to_add.each do |new_track|
+          existing_track = track_class.new
+
+          blk.call(existing_track, new_track)
+
+          if existing_track.save
+            result.push(existing_track)
+          else
+            result = existing_track
+            raise ActiveRecord::Rollback
+          end
+        end
+
+        to_delete.each do |delete_me|
+          delete_me.delete
+        end
+      end
+      result
+    end
 
     # this is a bit different from a normal track synchronization in that the client just sends up all tracks,
     # ... some may already exist
-    def self.sync(clientId, tracks)
-      result = []
+    def self.sync(clientId, tracks, backing_tracks = [])
+      result = {}
+
+      backing_tracks = [] unless backing_tracks
 
       Track.transaction do
         connection = Connection.find_by_client_id!(clientId)
@@ -68,67 +121,28 @@ module JamRuby
         msh = MusicSessionUserHistory.find_by_client_id!(clientId)
         instruments = []
 
-        if tracks.length == 0
-          connection.tracks.delete_all
-        else
-          connection_tracks = connection.tracks
+        tracks.each do |track|
+          instruments << track[:instrument_id]
+        end
 
-          # we will prune from this as we find matching tracks
-          to_delete = Set.new(connection_tracks)
-          to_add = Array.new(tracks)
+        result[:tracks] = diff_track(Track, connection.tracks, tracks) do |track_record, track_info|
+          track_record.connection = connection
+          track_record.client_track_id = track_info[:client_track_id]
+          track_record.client_resource_id = track_info[:client_resource_id]
+          track_record.instrument_id = track_info[:instrument_id]
+          track_record.sound = track_info[:sound]
+        end
 
-          tracks.each do |track|
-            instruments << track[:instrument_id]
-          end
+        result[:backing_tracks] = diff_track(BackingTrack, connection.backing_tracks, backing_tracks)  do |track_record, track_info|
+          track_record.connection = connection
+          track_record.client_track_id = track_info[:client_track_id]
+          track_record.client_resource_id = track_info[:client_resource_id]
+          track_record.filename = track_info[:filename]
+        end
 
-          connection_tracks.each do |connection_track|
-            tracks.each do |track|
-
-              if track[:id] == connection_track.id || track[:client_track_id] == connection_track.client_track_id
-                to_delete.delete(connection_track)
-                to_add.delete(track)
-                # don't update connection_id or client_id; it's unknown what would happen if these changed mid-session
-                connection_track.instrument_id = track[:instrument_id]
-                connection_track.sound = track[:sound]
-                connection_track.client_track_id = track[:client_track_id]
-                connection_track.client_resource_id = track[:client_resource_id]
-
-                result.push(connection_track)
-
-                if connection_track.save
-                  next
-                else
-                  result = connection_track
-                  raise ActiveRecord::Rollback
-                end
-
-              end
-            end
-          end
-
-          msh.instruments = instruments.join("|")
-          if !msh.save
-            raise ActiveRecord::Rollback
-          end
-
-          to_add.each do |track|
-            connection_track = Track.new
-            connection_track.connection = connection
-            connection_track.instrument_id = track[:instrument_id]
-            connection_track.sound = track[:sound]
-            connection_track.client_track_id = track[:client_track_id]
-            connection_track.client_resource_id = track[:client_resource_id]
-            if connection_track.save
-              result.push(connection_track)
-            else
-              result = connection_track
-              raise ActiveRecord::Rollback
-            end
-          end
-
-          to_delete.each do |delete_me|
-            delete_me.delete
-          end
+        msh.instruments = instruments.join("|")
+        if !msh.save
+          raise ActiveRecord::Rollback
         end
       end
 

ruby/lib/jam_ruby/models/user.rb

@@ -122,6 +122,7 @@ module JamRuby
     # saved tracks
     has_many :recorded_tracks, :foreign_key => "user_id", :class_name => "JamRuby::RecordedTrack", :inverse_of => :user
     has_many :recorded_videos, :foreign_key => "user_id", :class_name => "JamRuby::RecordedVideo", :inverse_of => :user
+    has_many :recorded_backing_tracks, :foreign_key => "user_id", :class_name => "JamRuby::RecordedBackingTrack", :inverse_of => :user
     has_many :quick_mixes, :foreign_key => "user_id", :class_name => "JamRuby::QuickMix", :inverse_of => :user
 
     # invited users

ruby/lib/jam_ruby/models/user_sync.rb

@@ -4,6 +4,7 @@ module JamRuby
     belongs_to :recorded_track
     belongs_to :mix
     belongs_to :quick_mix
+    belongs_to :recorded_backing_track
 
     def self.show(id, user_id)
       self.index({user_id: user_id, id: id, limit: 1, offset: 0})[:query].first
@@ -22,7 +23,7 @@ module JamRuby
       raise 'no user id specified' if user_id.blank?
 
       query = UserSync
-        .includes(recorded_track: [{recording: [:owner, {claimed_recordings: [:share_token]}, {recorded_tracks: [:user]}, {comments:[:user]}, :likes, :plays, :mixes]}, user: [], instrument:[]], mix: [], quick_mix:[])
+        .includes(recorded_track: [{recording: [:owner, {claimed_recordings: [:share_token]}, {recorded_tracks: [:user]}, {comments:[:user]}, :likes, :plays, :mixes]}, user: [], instrument:[]], mix: [], quick_mix:[], recorded_backing_track:[])
         .joins("LEFT OUTER JOIN claimed_recordings ON claimed_recordings.user_id = user_syncs.user_id AND claimed_recordings.recording_id = user_syncs.recording_id")
         .where(user_id: user_id)
         .where(%Q{

ruby/spec/factories.rb

@@ -232,6 +232,11 @@ FactoryGirl.define do
     sequence(:client_resource_id) { |n| "resource_id#{n}"}
   end
 
+  factory :backing_track, :class => JamRuby::BackingTrack do
+    sequence(:client_track_id) { |n| "client_track_id#{n}"}
+    filename 'foo.mp3'
+  end
+
   factory :video_source, :class => JamRuby::VideoSource do
     #client_video_source_id "test_source_id"    
     sequence(:client_video_source_id) { |n| "client_video_source_id#{n}"}
@@ -250,6 +255,20 @@ FactoryGirl.define do
     association :recording,     factory: :recording
   end
 
+  factory :recorded_backing_track, :class => JamRuby::RecordedBackingTrack do
+    sequence(:client_id) { |n| "client_id-#{n}"}
+    sequence(:backing_track_id) { |n| "track_id-#{n}"}
+    sequence(:client_track_id) { |n| "client_track_id-#{n}"}
+    sequence(:filename) { |n| "filename-{#n}"}
+    sequence(:url) { |n| "/recordings/blah/#{n}"}
+    md5 'abc'
+    length 1
+    fully_uploaded true
+    association :user,          factory: :user
+    association :recording,     factory: :recording
+  end
+
+
   factory :recorded_video, :class => JamRuby::RecordedVideo do 
     sequence(:client_video_source_id) { |n| "client_video_source_id-#{n}"}
     fully_uploaded true

ruby/spec/jam_ruby/models/active_music_session_spec.rb

@@ -745,6 +745,29 @@ describe ActiveMusicSession do
         @music_session.errors[:claimed_recording] == [ValidationMessages::JAM_TRACK_ALREADY_OPEN]
 
       end
+
+      it "disallow a claimed recording to be started when backing track is open" do
+        # open the backing track
+        @backing_track = "foo.mp3"
+        @music_session.open_backing_track(@user1, @backing_track)
+        @music_session.errors.any?.should be_false
+
+        # and try to open a recording for playback
+        @music_session.claimed_recording_start(@user1, @claimed_recording)
+        @music_session.errors.any?.should be_true
+        @music_session.errors[:claimed_recording] == [ValidationMessages::BACKING_TRACK_ALREADY_OPEN]
+      end
+
+      it "disallow a claimed recording to be started when metronome is open" do
+        # open the metronome
+        @music_session.open_metronome(@user1)
+        @music_session.errors.any?.should be_false
+
+        # and try to open a recording for playback
+        @music_session.claimed_recording_start(@user1, @claimed_recording)
+        @music_session.errors.any?.should be_true
+        @music_session.errors[:claimed_recording] == [ValidationMessages::METRONOME_ALREADY_OPEN]
+      end
     end
   end
 
@@ -830,5 +853,143 @@ describe ActiveMusicSession do
       music_sessions[0].connections[0].tracks.should have(1).items
     end
   end
+  
+  describe "open_backing_track" do
+    before(:each) do
+      @user1 = FactoryGirl.create(:user)
+      @connection = FactoryGirl.create(:connection, :user => @user1)
+      @instrument = FactoryGirl.create(:instrument, :description => 'a great instrument')
+      @track = FactoryGirl.create(:track, :connection => @connection, :instrument => @instrument)
+      @music_session = FactoryGirl.create(:active_music_session, :creator => @user1, :musician_access => true)
+      # @music_session.connections << @connection
+      @music_session.save!
+      @connection.join_the_session(@music_session, true, nil, @user1, 10)
+      @backing_track = "foo/bar.mp3"      
+    end
+
+    it "allow a backing track to be associated" do
+      # simple success case; just open the backing track and observe the state of the session is correct
+      @music_session.open_backing_track(@user1, @backing_track)
+      @music_session.errors.any?.should be_false
+      @music_session.reload
+      @music_session.backing_track_path.should == @backing_track
+      @music_session.backing_track_initiator.should == @user1
+    end
+
+    it "allow a backing track to be closed" do
+      # simple success case; close an opened backing track and observe the state of the session is correct
+      @music_session.open_backing_track(@user1, @backing_track)
+      @music_session.errors.any?.should be_false
+      @music_session.close_backing_track
+      @music_session.errors.any?.should be_false
+      @music_session.reload
+      @music_session.backing_track_path.should be_nil
+      @music_session.backing_track_initiator.should be_nil
+    end
+
+    it "disallow a backing track to be opened when another is already opened" do
+      # if a backing track is open, don't allow another to be opened
+      @music_session.open_backing_track(@user1, @backing_track)
+      @music_session.errors.any?.should be_false
+      @music_session.open_backing_track(@user1, @backing_track)
+      @music_session.errors.any?.should be_true
+      @music_session.errors[:backing_track] == [ValidationMessages::BACKING_TRACK_ALREADY_OPEN]
+    end
+
+    it "disallow a backing track to be opened when recording is ongoing" do
+      @recording = Recording.start(@music_session, @user1)
+      @music_session.errors.any?.should be_false
+      @music_session.open_backing_track(@user1, @backing_track)
+      @music_session.errors.any?.should be_true
+      @music_session.errors[:backing_track] == [ValidationMessages::RECORDING_ALREADY_IN_PROGRESS]
+    end
+
+    it "disallow a backing track to be opened when recording is playing back" do
+      # create a recording, and open it for play back
+      @recording = Recording.start(@music_session, @user1)
+      @recording.errors.any?.should be_false
+      @recording.stop
+      @recording.reload
+      @claimed_recording = @recording.claim(@user1, "name", "description", Genre.first, true)
+      @claimed_recording.errors.any?.should be_false
+      @music_session.claimed_recording_start(@user1, @claimed_recording)
+      @music_session.errors.any?.should be_false
+
+      # while it's open, try to open a jam track
+      @music_session.open_backing_track(@user1, @backing_track)
+      @music_session.errors.any?.should be_true
+      @music_session.errors[:backing_track] == [ValidationMessages::CLAIMED_RECORDING_ALREADY_IN_PROGRESS]
+    end
+
+  end
+
+  describe "open_metronome" do
+    before(:each) do
+      @user1 = FactoryGirl.create(:user)
+      @connection = FactoryGirl.create(:connection, :user => @user1)
+      @instrument = FactoryGirl.create(:instrument, :description => 'a great instrument')
+      @track = FactoryGirl.create(:track, :connection => @connection, :instrument => @instrument)
+      @music_session = FactoryGirl.create(:active_music_session, :creator => @user1, :musician_access => true)
+      # @music_session.connections << @connection
+      @music_session.save!
+      @connection.join_the_session(@music_session, true, nil, @user1, 10)      
+    end
+
+    it "allow a metronome to be activated" do
+      # simple success case; just open the metronome and observe the state of the session is correct
+      @music_session.open_metronome(@user1)
+      @music_session.errors.any?.should be_false
+      @music_session.reload
+      @music_session.metronome_active.should == true
+      @music_session.metronome_initiator.should == @user1
+    end
+
+    it "allow a metronome to be closed" do
+      # simple success case; close an opened metronome and observe the state of the session is correct
+      @music_session.open_metronome(@user1)
+      @music_session.errors.any?.should be_false
+      @music_session.close_metronome
+      @music_session.errors.any?.should be_false
+      @music_session.reload
+      @music_session.metronome_active.should be_false
+      @music_session.metronome_initiator.should be_nil
+    end
+
+    it "disallow a metronome to be opened when another is already opened" do
+      # if a metronome is open, don't allow another to be opened
+      @music_session.open_metronome(@user1)
+      @music_session.errors.any?.should be_false
+      @music_session.open_metronome(@user1)
+      @music_session.errors.any?.should be_true
+      @music_session.errors[:metronome] == [ValidationMessages::METRONOME_ALREADY_OPEN]
+    end
+
+    it "disallow a metronome to be opened when recording is ongoing" do
+      @recording = Recording.start(@music_session, @user1)
+      @music_session.errors.any?.should be_false
+      @music_session.open_metronome(@user1)
+      @music_session.errors.any?.should be_true
+      @music_session.errors[:metronome] == [ValidationMessages::RECORDING_ALREADY_IN_PROGRESS]
+    end
+
+    it "disallow a metronome to be opened when recording is playing back" do
+      # create a recording, and open it for play back
+      @recording = Recording.start(@music_session, @user1)
+      @recording.errors.any?.should be_false
+      @recording.stop
+      @recording.reload
+      @claimed_recording = @recording.claim(@user1, "name", "description", Genre.first, true)
+      @claimed_recording.errors.any?.should be_false
+      @music_session.claimed_recording_start(@user1, @claimed_recording)
+      @music_session.errors.any?.should be_false
+
+      # while it's open, try to open a jam track
+      @music_session.open_metronome(@user1)
+      @music_session.errors.any?.should be_true
+      @music_session.errors[:metronome] == [ValidationMessages::CLAIMED_RECORDING_ALREADY_IN_PROGRESS]
+    end
+
+  end
+
 end
 

ruby/spec/jam_ruby/models/recorded_backing_track_spec.rb

@@ -0,0 +1,228 @@
+require 'spec_helper'
+require 'rest-client'
+
+describe RecordedBackingTrack do
+
+  include UsesTempFiles
+
+  before do
+    @user = FactoryGirl.create(:user)
+    @connection = FactoryGirl.create(:connection, :user => @user)
+    @instrument = FactoryGirl.create(:instrument, :description => 'a great instrument')
+    @music_session = FactoryGirl.create(:active_music_session, :creator => @user, :musician_access => true)
+    @track = FactoryGirl.create(:track, :connection => @connection, :instrument => @instrument)
+    @backing_track = FactoryGirl.create(:backing_track, :connection => @connection)
+    @recording = FactoryGirl.create(:recording, :music_session => @music_session, :owner => @user)
+  end
+
+  it "should copy from a regular track properly" do
+    @recorded_backing_track  = RecordedBackingTrack.create_from_backing_track(@backing_track, @recording)
+
+    @recorded_backing_track.user.id.should == @backing_track.connection.user.id
+    @recorded_backing_track.filename.should == @backing_track.filename
+    @recorded_backing_track.next_part_to_upload.should == 0
+    @recorded_backing_track.fully_uploaded.should == false
+    @recorded_backing_track.client_id = @connection.client_id
+    @recorded_backing_track.backing_track_id = @backing_track.id
+  end
+
+  it "should update the next part to upload properly" do
+    @recorded_backing_track  = RecordedBackingTrack.create_from_backing_track(@backing_track, @recording)
+    @recorded_backing_track.upload_part_complete(1, 1000)
+    @recorded_backing_track.errors.any?.should be_true
+    @recorded_backing_track.errors[:length][0].should == "is too short (minimum is 1 characters)"
+    @recorded_backing_track.errors[:md5][0].should == "can't be blank"
+  end
+
+  it "properly finds a recorded track given its upload filename" do
+    @recorded_backing_track  = RecordedBackingTrack.create_from_backing_track(@backing_track, @recording)
+    @recorded_backing_track.save.should be_true
+    RecordedBackingTrack.find_by_recording_id_and_backing_track_id(@recorded_backing_track.recording_id, @recorded_backing_track.backing_track_id).should == @recorded_backing_track
+  end
+
+  it "gets a url for the track" do
+    @recorded_backing_track  = RecordedBackingTrack.create_from_backing_track(@backing_track, @recording)
+    @recorded_backing_track.errors.any?.should be_false
+    @recorded_backing_track[:url].should == "recordings/#{@recorded_backing_track.created_at.strftime('%m-%d-%Y')}/#{@recording.id}/backing-track-#{@backing_track.client_track_id}.ogg"
+  end
+
+  it "signs url" do
+    stub_const("APP_CONFIG", app_config)
+    @recorded_backing_track  = RecordedBackingTrack.create_from_backing_track(@backing_track, @recording)
+    @recorded_backing_track.sign_url.should_not be_nil
+  end
+
+  it "can not be downloaded if no claimed recording" do
+    user2 = FactoryGirl.create(:user)
+    @recorded_backing_track  = RecordedBackingTrack.create_from_backing_track(@backing_track, @recording)
+    @recorded_backing_track.can_download?(user2).should be_false
+    @recorded_backing_track.can_download?(@user).should be_false
+  end
+
+  it "can be downloaded if there is a claimed recording" do
+    @recorded_track = RecordedTrack.create_from_track(@track, @recording)
+    @recorded_backing_track  = RecordedBackingTrack.create_from_backing_track(@backing_track, @recording)
+    @recording.claim(@user, "my recording", "my description", Genre.first, true).errors.any?.should be_false
+    @recorded_backing_track.can_download?(@user).should be_true
+  end
+
+
+  describe "aws-based operations", :aws => true do
+
+    def put_file_to_aws(signed_data, contents)
+
+      begin
+        RestClient.put( signed_data[:url],
+                        contents,
+                        {
+                            :'Content-Type' => 'audio/ogg',
+                            :Date => signed_data[:datetime],
+                            :'Content-MD5' => signed_data[:md5],
+                            :Authorization => signed_data[:authorization]
+                        })
+      rescue => e
+        puts e.response
+        raise e
+      end
+
+    end
+    # create a test file
+    upload_file='some_file.ogg'
+    in_directory_with_file(upload_file)
+
+    upload_file_contents="ogg binary stuff in here"
+    md5 = Base64.encode64(Digest::MD5.digest(upload_file_contents)).chomp
+    test_config = app_config
+    s3_manager = S3Manager.new(test_config.aws_bucket, test_config.aws_access_key_id, test_config.aws_secret_access_key)
+
+
+    before do
+      stub_const("APP_CONFIG", app_config)
+      # this block of code will fully upload a sample file to s3
+      content_for_file(upload_file_contents)
+      s3_manager.delete_folder('recordings') # keep the bucket clean to save cost, and make it easier if post-mortuem debugging
+
+
+    end
+
+    it "cant mark a part complete without having started it" do
+      @recorded_backing_track  = RecordedBackingTrack.create_from_backing_track(@backing_track, @recording)
+      @recorded_backing_track.upload_start(1000, "abc")
+      @recorded_backing_track.upload_part_complete(1, 1000)
+      @recorded_backing_track.errors.any?.should be_true
+      @recorded_backing_track.errors[:next_part_to_upload][0].should == ValidationMessages::PART_NOT_STARTED
+    end
+
+    it "no parts" do
+      @recorded_backing_track  = RecordedBackingTrack.create_from_backing_track(@backing_track, @recording)
+      @recorded_backing_track.upload_start(1000, "abc")
+      @recorded_backing_track.upload_next_part(1000, "abc")
+      @recorded_backing_track.errors.any?.should be_false
+      @recorded_backing_track.upload_part_complete(1, 1000)
+      @recorded_backing_track.errors.any?.should be_true
+      @recorded_backing_track.errors[:next_part_to_upload][0].should == ValidationMessages::PART_NOT_FOUND_IN_AWS
+    end
+
+    it "enough part failures reset the upload" do
+      @recorded_backing_track  = RecordedBackingTrack.create_from_backing_track(@backing_track, @recording)
+      @recorded_backing_track.upload_start(File.size(upload_file), md5)
+      @recorded_backing_track.upload_next_part(File.size(upload_file), md5)
+      @recorded_backing_track.errors.any?.should be_false
+      APP_CONFIG.max_track_part_upload_failures.times do |i|
+        @recorded_backing_track.upload_part_complete(@recorded_backing_track.next_part_to_upload, File.size(upload_file))
+        @recorded_backing_track.errors[:next_part_to_upload] == [ValidationMessages::PART_NOT_FOUND_IN_AWS]
+        part_failure_rollover = i == APP_CONFIG.max_track_part_upload_failures - 1
+        expected_is_part_uploading = !part_failure_rollover
+        expected_part_failures = part_failure_rollover ? 0 : i + 1
+        @recorded_backing_track.reload
+        @recorded_backing_track.is_part_uploading.should == expected_is_part_uploading
+        @recorded_backing_track.part_failures.should == expected_part_failures
+      end
+
+      @recorded_backing_track.reload
+      @recorded_backing_track.upload_failures.should == 1
+      @recorded_backing_track.file_offset.should == 0
+      @recorded_backing_track.next_part_to_upload.should == 0
+      @recorded_backing_track.upload_id.should be_nil
+      @recorded_backing_track.md5.should be_nil
+      @recorded_backing_track.length.should == 0
+    end
+
+    it "enough upload failures fails the upload forever" do
+      APP_CONFIG.stub(:max_track_upload_failures).and_return(1)
+      APP_CONFIG.stub(:max_track_part_upload_failures).and_return(2)
+      @recorded_backing_track  = RecordedBackingTrack.create_from_backing_track(@backing_track, @recording)
+      APP_CONFIG.max_track_upload_failures.times do |j|
+        @recorded_backing_track.upload_start(File.size(upload_file), md5)
+        @recorded_backing_track.upload_next_part(File.size(upload_file), md5)
+        @recorded_backing_track.errors.any?.should be_false
+        APP_CONFIG.max_track_part_upload_failures.times do |i|
+          @recorded_backing_track.upload_part_complete(@recorded_backing_track.next_part_to_upload, File.size(upload_file))
+          @recorded_backing_track.errors[:next_part_to_upload] == [ValidationMessages::PART_NOT_FOUND_IN_AWS]
+          part_failure_rollover = i == APP_CONFIG.max_track_part_upload_failures - 1
+          expected_is_part_uploading = part_failure_rollover ? false : true
+          expected_part_failures = part_failure_rollover ? 0 : i + 1
+          @recorded_backing_track.reload
+          @recorded_backing_track.is_part_uploading.should == expected_is_part_uploading
+          @recorded_backing_track.part_failures.should == expected_part_failures
+        end
+        @recorded_backing_track.upload_failures.should == j + 1
+      end
+
+      @recorded_backing_track.reload
+      @recorded_backing_track.upload_failures.should == APP_CONFIG.max_track_upload_failures
+      @recorded_backing_track.file_offset.should == 0
+      @recorded_backing_track.next_part_to_upload.should == 0
+      @recorded_backing_track.upload_id.should be_nil
+      @recorded_backing_track.md5.should be_nil
+      @recorded_backing_track.length.should == 0
+
+      # try to poke it and get the right kind of error back
+      @recorded_backing_track.upload_next_part(File.size(upload_file), md5)
+      @recorded_backing_track.errors[:upload_failures] = [ValidationMessages::UPLOAD_FAILURES_EXCEEDED]
+    end
+
+    describe "correctly uploaded a file" do
+
+      before do
+        @recorded_backing_track  = RecordedBackingTrack.create_from_backing_track(@backing_track, @recording)
+        @recorded_backing_track.upload_start(File.size(upload_file), md5)
+        @recorded_backing_track.upload_next_part(File.size(upload_file), md5)
+        signed_data = @recorded_backing_track.upload_sign(md5)
+        @response = put_file_to_aws(signed_data, upload_file_contents)
+        @recorded_backing_track.upload_part_complete(@recorded_backing_track.next_part_to_upload, File.size(upload_file))
+        @recorded_backing_track.errors.any?.should be_false
+        @recorded_backing_track.upload_complete
+        @recorded_backing_track.errors.any?.should be_false
+        @recorded_backing_track.marking_complete = false
+      end
+
+      it "can download an updated file" do
+        @response = RestClient.get @recorded_backing_track.sign_url
+        @response.body.should == upload_file_contents
+      end
+
+      it "can't mark completely uploaded twice" do
+        @recorded_backing_track.upload_complete
+        @recorded_backing_track.errors.any?.should be_true
+        @recorded_backing_track.errors[:fully_uploaded][0].should == "already set"
+        @recorded_backing_track.part_failures.should == 0
+      end
+
+      it "can't ask for a next part if fully uploaded" do
+        @recorded_backing_track.upload_next_part(File.size(upload_file), md5)
+        @recorded_backing_track.errors.any?.should be_true
+        @recorded_backing_track.errors[:fully_uploaded][0].should == "already set"
+        @recorded_backing_track.part_failures.should == 0
+      end
+
+      it "can't ask for mark part complete if fully uploaded" do
+        @recorded_backing_track.upload_part_complete(1, 1000)
+        @recorded_backing_track.errors.any?.should be_true
+        @recorded_backing_track.errors[:fully_uploaded][0].should == "already set"
+        @recorded_backing_track.part_failures.should == 0
+      end
+    end
+  end
+end
+

ruby/spec/jam_ruby/models/recording_spec.rb

@@ -211,6 +211,20 @@ describe Recording do
     user1_recorded_tracks[0].discard = true
     user1_recorded_tracks[0].save!
   end
+
+  it "should allow finding of backing tracks" do
+    user2 = FactoryGirl.create(:user)
+    connection2 = FactoryGirl.create(:connection, :user => user2, :music_session => @music_session)
+    track2 = FactoryGirl.create(:track, :connection => connection2, :instrument => @instrument)
+    backing_track = FactoryGirl.create(:backing_track, :connection => connection2)
+
+
+    @recording = Recording.start(@music_session, @user)
+    @recording.recorded_backing_tracks_for_user(@user).length.should eq(0)
+    user2_recorded_tracks = @recording.recorded_backing_tracks_for_user(user2)
+    user2_recorded_tracks.length.should == 1
+    user2_recorded_tracks[0].should == user2.recorded_backing_tracks[0]
+  end
   
   it "should set up the recording properly when recording is started with 1 user in the session" do
     @music_session.is_recording?.should be_false
@@ -547,6 +561,8 @@ describe Recording do
     @genre = FactoryGirl.create(:genre)
     @recording.claim(@user, "Recording", "Recording Description", @genre, true)
 
+    @backing_track = FactoryGirl.create(:backing_track, :connection => @connection)
+
     # We should have 2 items; a track and a video:
     uploads = Recording.list_uploads(@user)
     uploads["uploads"].should have(3).items

ruby/spec/jam_ruby/models/track_spec.rb

@@ -7,8 +7,10 @@ describe Track do
   let (:connection) { FactoryGirl.create(:connection, :user => user, :music_session => music_session) }
   let (:track) { FactoryGirl.create(:track, :connection => connection)}
   let (:track2) { FactoryGirl.create(:track, :connection => connection)}
+  let (:backing_track) { FactoryGirl.create(:backing_track, :connection => connection)}
   let (:msuh) {FactoryGirl.create(:music_session_user_history, :history => music_session.music_session, :user => user, :client_id => connection.client_id) }
   let (:track_hash) { {:client_track_id => 'client_guid', :sound => 'stereo', :instrument_id => 'drums'} }
+  let (:backing_track_hash) { {:client_track_id => 'client_guid', :filename => "blah.wav"} }
 
   before(:each) do
     msuh.touch
@@ -16,7 +18,8 @@ describe Track do
 
   describe "sync" do
     it "create one track" do
-      tracks = Track.sync(connection.client_id, [track_hash])
+      result = Track.sync(connection.client_id, [track_hash])
+      tracks = result[:tracks]
       tracks.length.should == 1
       track = tracks[0]
       track.client_track_id.should == track_hash[:client_track_id]
@@ -25,7 +28,8 @@ describe Track do
     end
 
     it "create two tracks" do
-      tracks = Track.sync(connection.client_id, [track_hash, track_hash])
+      result = Track.sync(connection.client_id, [track_hash, track_hash])
+      tracks = result[:tracks]
       tracks.length.should == 2
       track = tracks[0]
       track.client_track_id.should == track_hash[:client_track_id]
@@ -40,7 +44,8 @@ describe Track do
     it "delete only track" do
       track.id.should_not  be_nil
       connection.tracks.length.should == 1
-      tracks = Track.sync(connection.client_id, [])
+      result = Track.sync(connection.client_id, [])
+      tracks = result[:tracks]
       tracks.length.should == 0
     end
 
@@ -49,7 +54,8 @@ describe Track do
       track.id.should_not be_nil
       track2.id.should_not be_nil
       connection.tracks.length.should == 2
-      tracks = Track.sync(connection.client_id, [{:id => track.id, :client_track_id => 'client_guid_new', :sound => 'mono', :instrument_id => 'drums'}])
+      result = Track.sync(connection.client_id, [{:id => track.id, :client_track_id => 'client_guid_new', :sound => 'mono', :instrument_id => 'drums'}])
+      tracks = result[:tracks]
       tracks.length.should == 1
       found = tracks[0]
       found.id.should == track.id
@@ -62,7 +68,8 @@ describe Track do
       track.id.should_not be_nil
       track2.id.should_not be_nil
       connection.tracks.length.should == 2
-      tracks = Track.sync(connection.client_id, [{:client_track_id => track.client_track_id, :sound => 'mono', :instrument_id => 'drums'}])
+      result = Track.sync(connection.client_id, [{:client_track_id => track.client_track_id, :sound => 'mono', :instrument_id => 'drums'}])
+      tracks = result[:tracks]
       tracks.length.should == 1
       found = tracks[0]
       found.id.should == track.id
@@ -75,7 +82,8 @@ describe Track do
       track.id.should_not be_nil
       connection.tracks.length.should == 1
       set_updated_at(track, 1.days.ago)
-      tracks = Track.sync(connection.client_id, [{:id => track.id, :client_track_id => 'client_guid_new', :sound => 'mono', :instrument_id => 'drums'}])
+      result = Track.sync(connection.client_id, [{:id => track.id, :client_track_id => 'client_guid_new', :sound => 'mono', :instrument_id => 'drums'}])
+      tracks = result[:tracks]
       tracks.length.should == 1
       found = tracks[0]
       found.id.should == track.id
@@ -87,7 +95,8 @@ describe Track do
     it "updates a single track using .client_track_id to correlate" do
       track.id.should_not be_nil
       connection.tracks.length.should == 1
-      tracks = Track.sync(connection.client_id, [{:client_track_id => track.client_track_id, :sound => 'mono', :instrument_id => 'drums'}])
+      result = Track.sync(connection.client_id, [{:client_track_id => track.client_track_id, :sound => 'mono', :instrument_id => 'drums'}])
+      tracks = result[:tracks]
       tracks.length.should == 1
       found = tracks[0]
       found.id.should == track.id
@@ -99,11 +108,69 @@ describe Track do
       track.id.should_not be_nil
       connection.tracks.length.should == 1
       set_updated_at(track, 1.days.ago)
-      tracks = Track.sync(connection.client_id, [{:id => track.id, :client_track_id => track.client_track_id, :sound => track.sound, :instrument_id => track.instrument_id, client_resource_id: track.client_resource_id}])
+      result = Track.sync(connection.client_id, [{:id => track.id, :client_track_id => track.client_track_id, :sound => track.sound, :instrument_id => track.instrument_id, client_resource_id: track.client_resource_id}])
+      tracks = result[:tracks]
       tracks.length.should == 1
       found = tracks[0]
       expect(found.id).to eq track.id
       expect(found.updated_at.to_i).to eq track.updated_at.to_i
     end
+
+    describe "backing tracks" do
+      it "create one track and one backing track" do
+        result = Track.sync(connection.client_id, [track_hash], [backing_track_hash])
+        tracks = result[:tracks]
+        tracks.length.should == 1
+        track = tracks[0]
+        track.client_track_id.should == track_hash[:client_track_id]
+        track.sound = track_hash[:sound]
+        track.instrument.should == Instrument.find('drums')
+
+        backing_tracks = result[:backing_tracks]
+        backing_tracks.length.should == 1
+        track = backing_tracks[0]
+        track.client_track_id.should == backing_track_hash[:client_track_id]
+      end
+
+      it "delete only backing_track" do
+        track.id.should_not be_nil
+        backing_track.id.should_not be_nil
+        connection.tracks.length.should == 1
+        connection.backing_tracks.length.should == 1
+        result = Track.sync(connection.client_id,
+                            [{:id => track.id, :client_track_id => track.client_track_id, :sound => track.sound, :instrument_id => track.instrument_id, client_resource_id: track.client_resource_id}],
+                            [])
+        tracks = result[:tracks]
+        tracks.length.should == 1
+        found = tracks[0]
+        expect(found.id).to eq track.id
+        expect(found.updated_at.to_i).to eq track.updated_at.to_i
+
+        backing_tracks = result[:backing_tracks]
+        backing_tracks.length.should == 0
+      end
+
+      it "does not touch updated_at when nothing changes" do
+        track.id.should_not be_nil
+        backing_track.id.should_not be_nil
+        connection.tracks.length.should == 1
+        set_updated_at(track, 1.days.ago)
+        set_updated_at(backing_track, 1.days.ago)
+        result = Track.sync(connection.client_id,
+                            [{:id => track.id, :client_track_id => track.client_track_id, :sound => track.sound, :instrument_id => track.instrument_id, client_resource_id: track.client_resource_id}],
+                            [{:id => backing_track.id, :client_track_id => backing_track.client_track_id, :filename => backing_track.filename, client_resource_id: backing_track.client_resource_id}])
+        tracks = result[:tracks]
+        tracks.length.should == 1
+        found = tracks[0]
+        expect(found.id).to eq track.id
+        expect(found.updated_at.to_i).to eq track.updated_at.to_i
+
+        backing_tracks = result[:backing_tracks]
+        backing_tracks.length.should == 1
+        found = backing_tracks[0]
+        expect(found.id).to eq backing_track.id
+        expect(found.updated_at.to_i).to eq backing_track.updated_at.to_i
+      end
+    end
   end
 end

ruby/spec/jam_ruby/models/user_sync_spec.rb

@@ -20,6 +20,49 @@ describe UserSync do
       data[:next].should be_nil
     end
 
+    describe "backing_tracks" do
+
+      let!(:recording1) {
+        recording = FactoryGirl.create(:recording, owner: user1, band: nil, duration:1)
+        recording.recorded_tracks << FactoryGirl.create(:recorded_track, recording: recording, user: recording.owner, fully_uploaded:false)
+        recording.recorded_tracks << FactoryGirl.create(:recorded_track, recording: recording, user: user2, fully_uploaded:false)
+        recording.recorded_backing_tracks << FactoryGirl.create(:recorded_backing_track, recording: recording, user: recording.owner, fully_uploaded:false)
+        recording.save!
+        recording.reload
+        recording
+      }
+
+      let(:sorted_tracks) {
+        Array.new(recording1.recorded_tracks).sort! {|a, b|
+          if a.created_at == b.created_at
+            a.id <=> b.id
+          else
+            a.created_at <=> b.created_at
+          end
+        }
+      }
+
+      # backing tracks should only list download, or upload, for the person who opened it, for legal reasons
+      it "lists backing track for opener" do
+        data = UserSync.index({user_id: user1.id})
+        data[:next].should be_nil
+        user_syncs = data[:query]
+        user_syncs.count.should eq(3)
+        user_syncs[0].recorded_track.should == sorted_tracks[0]
+        user_syncs[1].recorded_track.should == sorted_tracks[1]
+        user_syncs[2].recorded_backing_track.should == recording1.recorded_backing_tracks[0]
+      end
+
+      it "does not list backing track for non-opener" do
+        data = UserSync.index({user_id: user2.id})
+        data[:next].should be_nil
+        user_syncs = data[:query]
+        user_syncs.count.should eq(2)
+        user_syncs[0].recorded_track.should == sorted_tracks[0]
+        user_syncs[1].recorded_track.should == sorted_tracks[1]
+      end
+    end
+
     it "one mix and quick mix" do
       mix = FactoryGirl.create(:mix)
       mix.recording.duration = 1

ruby/spec/spec_helper.rb

@@ -46,6 +46,7 @@ ActiveRecord::Base.add_observer InvitedUserObserver.instance
 ActiveRecord::Base.add_observer UserObserver.instance
 ActiveRecord::Base.add_observer FeedbackObserver.instance
 ActiveRecord::Base.add_observer RecordedTrackObserver.instance
+ActiveRecord::Base.add_observer RecordedBackingTrackObserver.instance
 ActiveRecord::Base.add_observer QuickMixObserver.instance
 
 #RecordedTrack.observers.disable :all # only a few tests want this observer active

web/Gemfile

@@ -75,7 +75,7 @@ gem 'netaddr'
 gem 'quiet_assets', :group => :development
 gem 'bugsnag'
 gem 'multi_json', '1.9.0'
-gem 'rest_client'
+gem 'rest-client'
 gem 'iso-639'
 gem 'language_list'
 gem 'rubyzip'

web/README.md

@@ -1,6 +1,3 @@
-TODO: 
-====
-
 Jasmine Javascript Unit Tests
 =============================
 
@@ -11,5 +8,3 @@ $ bundle
 $ rake jasmine
 
 Open browser to localhost:8888
-
-

web/app/assets/javascripts/dialog/localRecordingsDialog.js

@@ -112,6 +112,10 @@
                    // tell the server we are about to start a recording
                    rest.startPlayClaimedRecording({id: context.JK.CurrentSessionModel.id(), claimed_recording_id: claimedRecording.id})
                        .done(function(response) {
+
+                           // update session info
+                           context.JK.CurrentSessionModel.updateSession(response);
+
                            var recordingId = $(this).attr('data-recording-id');
                            var openRecordingResult = context.jamClient.OpenRecording(claimedRecording.recording);
 

web/app/assets/javascripts/dialog/openBackingTrackDialog.js

@@ -0,0 +1,147 @@
+(function(context,$) {
+
+  "use strict";
+  context.JK = context.JK || {};
+  context.JK.OpenBackingTrackDialog = function(app) {
+    var logger = context.JK.logger;
+    var rest = context.JK.Rest();
+    var showing = false;
+    var perPage = 10;
+    var $dialog = null;
+    var $tbody = null;
+    var $paginatorHolder = null;
+    var $templateOpenBackingTrackRow = null;
+    var $downloadedTrackHelp = null;
+    var $whatAreBackingTracks = null;
+    var $displayAudioFileFolder = null;
+
+
+    function emptyList() {
+      $tbody.empty();
+    }
+
+    function resetPagination() {
+      $dialog.find('.paginator').remove();
+    }
+
+    function beforeShow() {
+      emptyList();
+      resetPagination();
+      showing = true;
+      getBackingTracks();
+      $dialog.data('result', null);
+        // .done(function(data, textStatus, jqXHR) {
+        //   // initialize pagination
+        //   var $paginator = context.JK.Paginator.create(parseInt(jqXHR.getResponseHeader('total-entries')), perPage, 0, onPageSelected)
+        //   $paginatorHolder.append($paginator);
+        // });
+    }
+
+    function afterHide() {
+      showing = false;
+    }
+
+
+    function onPageSelected(targetPage) {
+      return getBackingTracks(targetPage);
+    }
+
+    function getBackingTracks(page) {
+
+      var result = context.jamClient.getBackingTrackList();
+      console.log("result", result)
+      var backingTracks = result.backing_tracks;
+          
+      if (!backingTracks || backingTracks.length == 0) {
+        $tbody.append("<tr><td colspan='100%'>No Tracks found</td></tr>");
+      } else {
+        $.each(backingTracks, function(index, backingTrack) {
+          var extension = backingTrack.name
+          var options = {
+            backingTrackState: null,
+            name: backingTrack.name,
+            type: getExtension(backingTrack.name),
+            length: displaySize(backingTrack.size)
+          }
+          var $tr = $(context._.template($templateOpenBackingTrackRow.html(), options, { variable: 'data' }));
+          $tr.data('server-model', backingTrack);
+          $tbody.append($tr);
+        });        
+      }//end      
+    }
+
+    // from http://stackoverflow.com/questions/190852/how-can-i-get-file-extensions-with-javascript
+    function getExtension(filename) {
+      return filename.substr((~-filename.lastIndexOf(".") >>> 0) + 2)
+    }
+
+    // from seth:
+    function displaySize(length) {
+      var size = (length==null || typeof(length)=='undefined') ? 0 : Number(length)
+      return (Math.round(size * 10 / (1024 * 1024) ) / 10).toString() + "M"
+    }    
+
+    function registerStaticEvents() {
+      $tbody.on('click', 'tr', function(e) {
+        var backingTrack = $(this).data('server-model');
+
+        // tell the server we are about to open a backing track:
+        rest.openBackingTrack({id: context.JK.CurrentSessionModel.id(), backing_track_path: backingTrack.name})
+          .done(function(response) {
+            var result = context.jamClient.SessionOpenBackingTrackFile(backingTrack.name, false);
+            console.log("BackingTrackPlay response: %o", result);
+
+            // TODO: Possibly actually check the result.  Investigate
+            // what real client returns:
+            // // if(result) {
+                // let callers see which backing track was chosen
+                $dialog.data('result', backingTrack);
+                app.layout.closeDialog('open-backing-track-dialog');
+            // }
+            // else {
+            //   logger.error("unable to open backing track")
+            // }
+            context.JK.CurrentSessionModel.refreshCurrentSession(true);
+
+          })
+          .fail(function(jqXHR) {
+            app.notifyServerError(jqXHR, "Unable to Open BackingTrack For Playback");
+          })
+
+        return false;
+      })
+
+      context.JK.helpBubble($whatAreBackingTracks, 'no help yet for this topic', {}, {positions:['bottom'], offsetParent: $dialog})
+      $whatAreBackingTracks.on('click', false) // no help yet
+
+      $displayAudioFileFolder.on('click', function(e) {
+        e.stopPropagation();
+        context.jamClient.OpenBackingTracksDirectory();        
+      })
+    }
+
+    function initialize(){
+      var dialogBindings = {
+        'beforeShow' : beforeShow,
+        'afterHide': afterHide
+      };
+
+      app.bindDialog('open-backing-track-dialog', dialogBindings);
+
+      $dialog = $('#open-backing-track-dialog');
+      $tbody = $dialog.find('table.open-backing-tracks tbody');
+      $paginatorHolder = $dialog.find('.paginator-holder');
+      $templateOpenBackingTrackRow = $('#template-backing-track-row')
+      $whatAreBackingTracks = $dialog.find('.what-are-backingtracks')
+      $displayAudioFileFolder = $dialog.find('.display-backingtracks-folder')
+
+      registerStaticEvents();
+    };
+
+
+    this.initialize = initialize;
+    this.isShowing = function isShowing() { return showing; }
+  }
+
+  return this;
+})(window,jQuery);

web/app/assets/javascripts/dialog/recordingFinishedDialog.js

@@ -78,6 +78,23 @@
               "icon_url": "/assets/content/icon_alert_big.png"
             });
           }
+          else {
+            // hunt for missing backing tracks; if so, mark them as silent
+            context._.each(openRecordingResult.backing_tracks, function(backingTrack) {
+              if(backingTrack.local_state == "MISSING") {
+                // mark this as deleted
+                logger.debug("marking recorded track as deleted")
+                rest.markRecordedBackingTrackSilent({recording_id: openRecordingResult.recording_id, backing_track_id: backingTrack.client_track_id})
+                  .fail(function() {
+                    app.notify({
+                      "title": "Unable to Mark Backing Track",
+                      "text": "A backing track was never played, but we could not tell the server to remove it from the recording.",
+                      "icon_url": "/assets/content/icon_alert_big.png"
+                    });
+                  })
+              }
+            })
+          }
 
           playbackControls.startMonitor();
         }

web/app/assets/javascripts/fakeJamClient.js

@@ -21,6 +21,12 @@
         var frameSize = 2.5;
         var fakeJamClientRecordings = null;
         var p2pCallbacks = null;
+        var metronomeActive=false;
+        var metronomeBPM=false;
+        var metronomeSound=false;
+        var metronomeMeter=0;
+        var backingTrackPath="";
+        var backingTrackLoop=false;
 
         function dbg(msg) { logger.debug('FakeJamClient: ' + msg); }
 
@@ -398,21 +404,42 @@
         }
         function SessionGetControlState(mixerIds, isMasterOrPersonal) {
             dbg("SessionGetControlState");
-            var groups = [0, 1, 2, 3, 7, 9];
+            var groups = [0, 1, 2, 3, 3, 7, 8, 10, 11, 12];
             var names = [
                 "FW AP Multi",
                 "FW AP Multi",
                 "FW AP Multi",
                 "FW AP Multi",
                 "",
-                ""
+                "",
+                "",
+                "",
+                "",
+                ""                
             ];
+
+            var media_types = [
+                "Master",
+                "Monitor",
+                "AudioInputMusic",
+                "AudioInputChat",
+                "StreamOutMusic",
+                "UserMusicInput",
+                "PeerAudioInputMusic",
+                "PeerMediaTrack",
+                "JamTrack",
+                "MetronomeTrack"
+            ]
             var clientIds = [
                 "",
                 "",
                 "",
                 "",
                 "3933ebec-913b-43ab-a4d3-f21dc5f8955b",
+                "",
+                "",
+                "",
+                "",
                 ""
             ];
             var response = [];
@@ -422,6 +449,7 @@
                     group_id: groups[i],
                     id: mixerIds[i] + (isMasterOrPersonal ? 'm' : 'p'),
                     master: isMasterOrPersonal,
+                    media_type: media_types[i],
                     monitor: !isMasterOrPersonal,
                     mute: false,
                     name: names[i],
@@ -686,6 +714,55 @@
         function GetScoreWorkTimingInterval() { return {interval: 1000, backoff:60000} }
         function SetScoreWorkTimingInterval(knobs) {return true;}
 
+        function SessionOpenBackingTrackFile(path, loop) {
+            backingTrackPath = path
+            backingTrackLoop = loop
+        }
+
+        function SessionSetBackingTrackFileLoop(path, loop) {
+            backingTrackPath = path
+            backingTrackLoop = loop            
+        }
+
+        function SessionCloseBackingTrackFile(path) {
+            backingTrackPath=""
+        }
+
+        function SessionOpenMetronome(bpm, click, meter, mode){
+            console.log("Setting metronome BPM: ", bpm)
+            metronomeActive =true
+            metronomeBPM = bpm
+            metronomeSound = click
+            metronomeMeter = meter
+        }
+        
+        //change setting - click. Mode 0: = mono, 1, = left ear, 2= right ear
+        function SessionSetMetronome(bpm,click,meter, mode){
+            SessionOpenMetronome(bpm, click, meter, mode)
+        }
+
+        //close everywhere
+        function SessionCloseMetronome(){
+            metronomeActive=false
+        }
+
+        function setMetronomeOpenCallback(callback) {
+
+        }
+
+        function getMyNetworkState() {
+            return {
+                ntp_stable: Math.random() > 0.5
+            }
+        }
+
+        function getPeerState(clientId) {
+            return {
+                ntp_stable: Math.random() > 0.5
+            }
+        }
+
+
         // stun
         function NetworkTestResult() { return {remote_udp_blocked: false} }
 
@@ -717,6 +794,14 @@
             fire();
 
         }
+
+        function getBackingTrackList() {
+            return {backing_tracks: [
+              {name:"This is a really long name for a song dude.mp3", size:4283},
+              {name:"foo.mp3",size:325783838}
+            ]};
+        }
+
         function ClientUpdateStartUpdate(path, successCallback, failureCallback) {}
 
         // -------------------------------
@@ -977,6 +1062,20 @@
         this.GetScoreWorkTimingInterval = GetScoreWorkTimingInterval;
         this.SetScoreWorkTimingInterval = SetScoreWorkTimingInterval;
 
+        // Backing tracks:
+        this.getBackingTrackList = getBackingTrackList;
+        this.SessionCloseBackingTrackFile = SessionCloseBackingTrackFile;
+        this.SessionOpenBackingTrackFile = SessionOpenBackingTrackFile;
+        this.SessionSetBackingTrackFileLoop = SessionSetBackingTrackFileLoop;
+
+        // Metronome:
+        this.SessionCloseMetronome = SessionCloseMetronome;
+        this.SessionOpenMetronome = SessionOpenMetronome;
+        this.SessionSetMetronome = SessionSetMetronome;
+        this.setMetronomeOpenCallback = setMetronomeOpenCallback;
+        this.getMyNetworkState = getMyNetworkState;
+        this.getPeerState = getPeerState;
+
         // Client Update
         this.IsAppInWritableVolume = IsAppInWritableVolume;
         this.ClientUpdateVersion = ClientUpdateVersion;

web/app/assets/javascripts/jam_rest.js

@@ -1043,6 +1043,18 @@
             })
         }
 
+        function markRecordedBackingTrackSilent(options) {
+          var recordingId = options["recording_id"];
+          var trackId = options["backing_track_id"];
+
+          return $.ajax({
+            type: "POST",
+            dataType: "json",
+            contentType: 'application/json',
+            data: {},
+            url: "/api/recordings/" + recordingId + "/backing_tracks/" + trackId + '/silent'
+          });
+        }
         function getRecordedTrack(options) {
           var recordingId = options["recording_id"];
           var trackId = options["track_id"];
@@ -1055,6 +1067,18 @@
           });
         }
 
+        function getRecordedBackingTrack(options) {
+          var recordingId = options["recording_id"];
+          var trackId = options["track_id"];
+
+          return $.ajax({
+            type: "GET",
+            dataType: "json",
+            contentType: 'application/json',
+            url: "/api/recordings/" + recordingId + "/backing_tracks/" + trackId
+          });
+        }
+
         function getRecording(options) {
             var recordingId = options["id"];
 
@@ -1157,6 +1181,32 @@
             })
         }
 
+        function openBackingTrack(options) {
+          var musicSessionId = options["id"];
+          delete options["id"];
+          
+          return $.ajax({
+            type: "POST",
+            dataType: "json",
+            contentType: 'application/json',
+            url: "/api/sessions/" + musicSessionId + "/backing_tracks/open",
+            data: JSON.stringify(options)
+          })
+        }
+
+        function closeBackingTrack(options) {
+          var musicSessionId = options["id"];
+          delete options["id"];
+
+          return $.ajax({
+            type: "POST",
+            dataType: "json",
+            contentType: 'application/json',
+            url: "/api/sessions/" + musicSessionId + "/backing_tracks/close",
+            data: JSON.stringify(options)
+          })
+        }
+
         function openJamTrack(options) {
           var musicSessionId = options["id"];
           var jamTrackId = options["jam_track_id"];
@@ -1185,6 +1235,32 @@
           })
         }
 
+        function openMetronome(options) {
+          var musicSessionId = options["id"];
+          delete options["id"];
+          
+          return $.ajax({
+            type: "POST",
+            dataType: "json",
+            contentType: 'application/json',
+            url: "/api/sessions/" + musicSessionId + "/metronome/open",
+            data: JSON.stringify(options)
+          })
+        }
+        
+        function closeMetronome(options) {
+          var musicSessionId = options["id"];
+          delete options["id"];
+          
+          return $.ajax({
+            type: "POST",
+            dataType: "json",
+            contentType: 'application/json',
+            url: "/api/sessions/" + musicSessionId + "/metronome/close",
+            data: JSON.stringify(options)
+          })
+        }
+        
         function discardRecording(options) {
             var recordingId = options["id"];
 
@@ -1367,6 +1443,15 @@
           });
         }
 
+        function getBackingTracks(options) {
+          return $.ajax({
+            type: "GET",
+            url: '/api/backing_tracks?' + $.param(options),
+            dataType: "json",
+            contentType: 'application/json'
+          });
+        }
+
         function addJamtrackToShoppingCart(options) {
           return $.ajax({
             type: "POST",
@@ -1563,6 +1648,7 @@
         this.stopRecording = stopRecording;
         this.getRecording = getRecording;
         this.getRecordedTrack = getRecordedTrack;
+        this.getRecordedBackingTrack = getRecordedBackingTrack;
         this.getClaimedRecordings = getClaimedRecordings;
         this.getClaimedRecording = getClaimedRecording;
         this.updateClaimedRecording = updateClaimedRecording;
@@ -1571,8 +1657,13 @@
         this.claimRecording = claimRecording;
         this.startPlayClaimedRecording = startPlayClaimedRecording;
         this.stopPlayClaimedRecording = stopPlayClaimedRecording;
-        this.openJamTrack = openJamTrack;
+        this.openJamTrack = openJamTrack
+        this.openBackingTrack = openBackingTrack
+        this.closeBackingTrack = closeBackingTrack
+        this.closeMetronome = closeMetronome;        
         this.closeJamTrack = closeJamTrack;
+        this.openMetronome = openMetronome;
+        this.closeMetronome = closeMetronome;
         this.discardRecording = discardRecording;
         this.putTrackSyncChange = putTrackSyncChange;
         this.createBand = createBand;
@@ -1603,6 +1694,7 @@
         this.updateAudioLatency = updateAudioLatency;
         this.getJamtracks = getJamtracks;
         this.getPurchasedJamTracks = getPurchasedJamTracks;
+        this.getBackingTracks = getBackingTracks;
         this.addJamtrackToShoppingCart = addJamtrackToShoppingCart;
         this.getShoppingCarts = getShoppingCarts;
         this.removeShoppingCart = removeShoppingCart;
@@ -1617,6 +1709,7 @@
         this.getMount = getMount;
         this.createSourceChange = createSourceChange;
         this.validateUrlSite = validateUrlSite;
+        this.markRecordedBackingTrackSilent = markRecordedBackingTrackSilent;
 
         return this;
     };

web/app/assets/javascripts/session.js

@@ -4,6 +4,7 @@
 
     context.JK = context.JK || {};
     context.JK.SessionScreen = function(app) {
+        var TEMPOS = context.JK.TEMPOS;
         var EVENTS = context.JK.EVENTS;
         var MIX_MODES = context.JK.MIX_MODES;
         var NAMED_MESSAGES = context.JK.NAMED_MESSAGES;
@@ -38,11 +39,14 @@
         var startTimeDate = null;
         var startingRecording = false; // double-click guard
         var claimedRecording = null;
+        var backing_track_path = null;
         var playbackControls = null;
         var promptLeave = false;
         var rateSessionDialog = null;
         var friendInput = null;
         var sessionPageDone = null;
+        var metroTempo = 120;
+        var metroSound = "Beep";
         var $recordingManagerViewer = null;
         var $screen = null;
         var $mixModeDropdown = null;
@@ -432,6 +436,7 @@
 
             var currentSession = sessionModel.getCurrentSession();
 
+
             if(claimedRecording == null  && (currentSession && currentSession.claimed_recording != null)) {
                 // this is a 'started with a claimed_recording' transition.
                 // we need to start a timer to watch for the state of the play session
@@ -440,10 +445,18 @@
             else if(claimedRecording && (currentSession == null || currentSession.claimed_recording == null)) {
                 playbackControls.stopMonitor();
             }
-
             claimedRecording = currentSession == null ? null : currentSession.claimed_recording;
 
+
+            if(backing_track_path == null && (currentSession && currentSession.backing_track_path != null)) {
+              playbackControls.startMonitor();
+            }
+            else if(backing_track_path && (currentSession == null || currentSession.backing_track_path == null)) {
+              playbackControls.stopMonitor();
+            }
+            backing_track_path = currentSession == null ? null : currentSession.backing_track_path;
         }
+
         function sessionChanged() {
 
             handleTransitionsInRecordingPlayback();
@@ -514,12 +527,21 @@
             if ($('.session-livetracks .track').length === 0) {
                 $('.session-livetracks .when-empty').show();
             }
+            
             if ($('.session-recordings .track').length === 0) {
                 $('.session-recordings .when-empty').show();
                 $('.session-recording-name-wrapper').hide();
                 $('.session-recordings .recording-controls').hide();
+            } else {
+                $('.session-recordings .when-empty').hide();
+                $('.session-recording-name-wrapper').show();
+                $('.session-recordings .recording-controls').show();
             }
-        }
+
+            // Handle long labels:
+            $(".track-label").dotdotdot()
+            $(".session-recording-name").dotdotdot()                        
+        } // renderSession
 
         function _initDialogs() {
             configureTrackDialog.initialize();
@@ -535,6 +557,7 @@
         function _updateMixers() {
             masterMixers = context.jamClient.SessionGetAllControlState(true);
             personalMixers = context.jamClient.SessionGetAllControlState(false);
+            context.jamClient 
 
             //logger.debug("masterMixers", masterMixers)
             //logger.debug("personalMixers", personalMixers)
@@ -674,7 +697,6 @@
           //logger.debug("clientId", clientId, "groupIds", groupIds, "mixers", mixers)
           var foundMixers = {};
           var mixers = mixMode == MIX_MODES.MASTER ? masterMixers : personalMixers;
-         // console.log("_groupedMixersForClientId", mixers)
           $.each(mixers, function(index, mixer) {
             if (mixer.client_id === clientId) {
               for (var i=0; i<groupIds.length; i++) {
@@ -811,11 +833,14 @@
         }
 
         function _renderLocalMediaTracks() {
-
+          //console.log("_renderLocalMediaTracks")
           // local media mixers come in different groups (MediaTrack, JamTrack, Metronome), but peer mixers are always PeerMediaTrackGroup
           var localMediaMixers = _mixersForGroupIds([ChannelGroupIds.MediaTrackGroup, ChannelGroupIds.JamTrackGroup, ChannelGroupIds.MetronomeGroup], MIX_MODES.MASTER);
           var peerLocalMediaMixers = _mixersForGroupId(ChannelGroupIds.PeerMediaTrackGroup, MIX_MODES.MASTER);
 
+          var recordedBackingTracks = sessionModel.recordedBackingTracks();
+          var backingTracks = sessionModel.backingTracks();
+
           // with mixer info, we use these to decide what kind of tracks are open in the backend
 
           // each mixer has a media_type field, which describes the type of media track it is.
@@ -836,31 +861,61 @@
           var metronomeTrackMixers = [];
           var adhocTrackMixers = [];
 
-          function groupByType(mixers) {
+          function groupByType(mixers, isLocalMixer) {
             context._.each(mixers, function(mixer) {
               var mediaType = mixer.media_type;
+              var groupId = mixer.group_id;
 
               // mediaType == null is for backwards compat with older clients.  Can be removed soon
               if(mediaType == null || mediaType == "" || mediaType == 'RecordingTrack') {
-                recordingTrackMixers.push(mixer)
-              }
-              else if(mediaType == 'BackingTrack') {
+                // additional check; if we can match an id in backing tracks or recorded backing track,
+                // we need to remove it from the recorded track set, but move it to the backing track set
+
+                var isBackingTrack = false
+                if(recordedBackingTracks) {
+                  context._.each(recordedBackingTracks, function (recordedBackingTrack) {
+                    if (mixer.id == 'L' + recordedBackingTrack.client_track_id) {
+                      isBackingTrack = true;
+                      return false; // break
+                    }
+                  })
+                }
+                if(backingTracks) {
+                  context._.each(backingTracks, function (backingTrack) {
+                    if (mixer.id == 'L' + backingTrack.client_track_id) {
+                      isBackingTrack = true;
+                      return false; // break
+                    }
+                  })
+                }
+
+                if(isBackingTrack) {
+                  backingTrackMixers.push(mixer)
+                }
+                else {
+                  recordingTrackMixers.push(mixer);
+                }
+              } else if(mediaType == 'PeerMediaTrack' || mediaType == 'BackingTrack') {
+                // BackingTrack
                 backingTrackMixers.push(mixer);
-              }
-              else if(mediaType == 'MetronomeTrack') {
+              } else if(mediaType == 'MetronomeTrack' || groupId==ChannelGroupIds.MetronomeGroup) {
+                // Metronomes come across with a blank media type, so check group_id:
                 metronomeTrackMixers.push(mixer);
-              }
-              else if(mediaType == 'JamTrack') {
+              } else if(mediaType == 'JamTrack') {
                 jamTrackMixers.push(mixer);
-              }
-              else {
+                mixer.group_id == ChannelGroupIds.MediaTrackGroup;
+              } else if(mediaType == null || mediaType == "" || mediaType == 'RecordingTrack') {
+                // mediaType == null is for backwards compat with older clients.  Can be removed soon
+                recordingTrackMixers.push(mixer)
+              } else {
+                logger.warn("Unknown track type: " + mediaType)
                 adhocTrackMixers.push(mixer);
               }
             });
           }
 
-          groupByType(localMediaMixers);
-          groupByType(peerLocalMediaMixers);
+          groupByType(localMediaMixers, true);
+          groupByType(peerLocalMediaMixers, false);
 
           if(recordingTrackMixers.length > 0) {
             renderRecordingTracks(recordingTrackMixers)
@@ -872,20 +927,131 @@
             renderJamTracks(jamTrackMixers);
           }
           if(metronomeTrackMixers.length > 0) {
-            renderMetronomeTracks(jamTrackMixers);
+            renderMetronomeTracks(metronomeTrackMixers);
           }
           if(adhocTrackMixers.length > 0) {
             logger.warn("some tracks are open that we don't know how to show")
           }
+
         }
 
-
+        // this method is pretty complicated because it forks on a key bit of state:
+        // sessionModel.isPlayingRecording()
+        // a backing track opened as part of a recording has a different behavior and presence on the server (recording.recorded_backing_tracks)
+        // than a backing track opend ad-hoc  (connection.backing_tracks)
         function renderBackingTracks(backingTrackMixers) {
-          logger.error("do not know how to draw backing tracks yet")
+
+          var backingTracks = []
+          if(sessionModel.isPlayingRecording()) {
+            // only return managed mixers for recorded backing tracks
+            backingTrackMixers = context._.filter(backingTrackMixers, function(mixer){return mixer.managed || mixer.managed === undefined})
+            backingTracks = sessionModel.recordedBackingTracks();
+          }
+          else {
+            // only return un-managed (ad-hoc) mixers for normal backing tracks
+            backingTracks = sessionModel.backingTracks();
+            backingTrackMixers = context._.filter(backingTrackMixers, function(mixer){return !mixer.managed})
+            if(backingTrackMixers.length > 1) {
+              app.notify({
+                title: "Multiple Backing Tracks Encountered",
+                text: "Only one backing track can be open a time.",
+                icon_url: "/assets/content/icon_alert_big.png"
+              });
+              return false;
+            }
+          }
+
+          var noCorrespondingTracks = false;
+          $.each(backingTrackMixers, function(index, mixer) {
+
+            console.log("hunting for backing tracks:", backingTrackMixers, backingTracks)
+            // find the track or tracks that correspond to the mixer
+            var correspondingTracks = []
+
+            var noCorrespondingTracks = false;
+            if(sessionModel.isPlayingRecording()) {
+              $.each(backingTracks, function (i, backingTrack) {
+                if(mixer.persisted_track_id == backingTrack.client_track_id || // occurs if this client is the one that opened the track
+                   mixer.id == 'L' + backingTrack.client_track_id) { // occurs if this client is a remote participant
+                  correspondingTracks.push(backingTrack)
+                }
+              });
+            }
+            else
+            {
+              // if this is just an open backing track, then we can assume that the 1st backingTrackMixer is ours
+              correspondingTracks.push(backingTracks[0])
+            }
+
+            if (correspondingTracks.length == 0) {
+              noCorrespondingTracks = true;
+              logger.debug("renderBackingTracks: could not map backing tracks")
+              app.notify({
+                title: "Unable to Open Backing Track",
+                text: "Could not correlate server and client tracks",
+                icon_url: "/assets/content/icon_alert_big.png"
+              });
+              return false;
+            }
+
+            // now we have backing track and mixer in hand; we can render
+            var backingTrack = correspondingTracks[0]
+
+            // pluck the 1st mixer, and assume that all other mixers in this group are of the same type (between JamTrack vs Peer)
+            // if it's a locally opened track (MediaTrackGroup), then we can say this person is the opener
+            var isOpener = mixer.group_id == ChannelGroupIds.MediaTrackGroup;
+
+            var shortFilename = context.JK.getNameOfFile(backingTrack.filename);
+
+            if(!sessionModel.isPlayingRecording()) {
+              // if a recording is being played back, do not set this header, because renderRecordedTracks already did
+              // ugly.
+              $('.session-recording-name').text(shortFilename);
+            }
+
+            var instrumentIcon = context.JK.getInstrumentIcon45(backingTrack.instrument_id);
+            var photoUrl = "/assets/content/icon_recording.png";
+
+
+            // Default trackData to participant + no Mixer state.
+            var trackData = {
+              trackId: backingTrack.id,
+              clientId: backingTrack.client_id,
+              name: 'Backing',
+              filename: backingTrack.filename,
+              instrumentIcon: instrumentIcon,
+              avatar: photoUrl,
+              latency: "good",
+              gainPercent: 0,
+              muteClass: 'muted',
+              showLoop: isOpener && !sessionModel.isPlayingRecording(),
+              mixerId: "",
+              avatarClass: 'avatar-recording',
+              preMasteredClass: ""
+            };
+
+            var gainPercent = percentFromMixerValue(
+              mixer.range_low, mixer.range_high, mixer.volume_left);
+            var muteClass = "enabled";
+            if (mixer.mute) {
+              muteClass = "muted";
+            }
+            trackData.gainPercent = gainPercent;
+            trackData.muteClass = muteClass;
+            trackData.mixerId = mixer.id; // the master mixer controls the volume control for recordings (no personal controls in either master or personal mode)
+            trackData.vuMixerId = mixer.id; // the master mixer controls the VUs for recordings (no personal controls in either master or personal mode)
+            trackData.muteMixerId = mixer.id; // the master mixer controls the mute for recordings (no personal controls in either master or personal mode)
+
+            if (sessionModel.isPersonalMixMode() || !isOpener) {
+              trackData.mediaControlsDisabled = true;
+              trackData.mediaTrackOpener = isOpener;
+            }
+            _addRecordingTrack(trackData, mixer);
+          });
         }
 
         function renderJamTracks(jamTrackMixers) {
-          log.debug("rendering jam tracks")
+          console.log("rendering jam tracks")
           var jamTracks = sessionModel.jamTracks();
 
           // pluck the 1st mixer, and assume that all other mixers in this group are of the same type (between JamTrack vs Peer)
@@ -901,7 +1067,6 @@
               var preMasteredClass = "";
               // find the track or tracks that correspond to the mixer
               var correspondingTracks = []
-              console.log("mixer", mixer)
               $.each(jamTracks, function(i, jamTrack) {
                 if(mixer.id.indexOf("L") == 0) {
                   if(mixer.id.substring(1) == jamTrack.id) {
@@ -909,7 +1074,7 @@
                   }
                   else {
                     // this should not be possible
-                    alert("Invalid state: the recorded track had neither persisted_track_id or persisted_client_id");
+                    alert("Invalid state: the backing track had neither persisted_track_id or persisted_client_id");
                   }
                 }
               });
@@ -981,13 +1146,107 @@
         }
 
         function renderMetronomeTracks(metronomeTrackMixers) {
-          logger.error("do not know how to draw metronome tracks yet")
+          var metronomeActive = sessionModel.metronomeActive();
+          console.log("rendering metronome track",metronomeActive)
+          
+          // pluck the 1st mixer, and assume that all other mixers in this group are of the same type (between JamTrack vs Peer)
+          // if it's a locally opened track (MediaTrackGroup), then we can say this person is the opener
+          var isOpener = metronomeTrackMixers[0].group_id == ChannelGroupIds.MediaTrackGroup;
+          var name = "Metronome"
+            
+          // using the server's info in conjuction with the client's, draw the recording tracks
+          if(metronomeActive && metronomeTrackMixers.length > 0) {
+            var metronome = {active: metronomeActive}
+            $('.session-recording-name').text(name);//sessionModel.getCurrentSession().backing_track_path);
+
+            var noCorrespondingTracks = false;
+            var mixer = metronomeTrackMixers[0]
+            var preMasteredClass = "";
+            // find the track or tracks that correspond to the mixer
+            var correspondingTracks = []
+            correspondingTracks.push(metronome);
+            
+            if(correspondingTracks.length == 0) {
+              noCorrespondingTracks = true;
+              app.notify({
+                title: "Unable to Open Metronome",
+                text: "Could not correlate server and client tracks",
+                icon_url: "/assets/content/icon_metronome_small.png"});
+              return false;
+            }
+
+            // prune found recorded tracks
+            // Metronomes = $.grep(Metronomes, function(value) {
+            //   return $.inArray(value, correspondingTracks) < 0;
+            // });
+
+            var oneOfTheTracks = correspondingTracks[0];
+            var instrumentIcon = context.JK.getInstrumentIcon45(oneOfTheTracks.instrument_id);
+            var photoUrl = "/assets/content/icon_metronome_small.png";
+
+            // var trackData = {
+            //   trackId: oneOfTheTracks.id,
+            //   clientId: oneOfTheTracks.client_id,
+            //   name: "Tempo",
+            //   instrumentIcon: photoUrl,
+            //   avatar: instrumentIcon,
+            //   latency: "good",
+            //   gainPercent: 0,
+            //   muteClass: 'hidden',
+            //   mixerId: "",
+            //   avatarClass : 'avatar-recording',
+            //   preMasteredClass: "",
+            //   hideVU: true,
+            //   faderChanged : tempoFaderChanged,
+            //   showMetronomeControls: true              
+            // };
+
+            // _addRecordingTrack(trackData);            
+
+            
+            // Default trackData to participant + no Mixer state.
+            var trackData = {
+              trackId: "MS" + oneOfTheTracks.id,
+              clientId: oneOfTheTracks.client_id,
+              name: "Metronome",
+              instrumentIcon: photoUrl,
+              avatar: instrumentIcon,
+              latency: "good",
+              gainPercent: 0,
+              muteClass: 'muted',
+              mixerId: "",
+              avatarClass : 'avatar-recording',
+              preMasteredClass: "",
+              showMetronomeControls: true
+            };
+
+            var gainPercent = percentFromMixerValue(
+              mixer.range_low, mixer.range_high, mixer.volume_left);
+            var muteClass = "enabled";
+            if (mixer.mute) {
+              muteClass = "muted";
+            }
+            trackData.gainPercent = gainPercent;
+            trackData.muteClass = muteClass;
+            trackData.mixerId = mixer.id; // the master mixer controls the volume control for recordings (no personal controls in either master or personal mode)
+            trackData.vuMixerId = mixer.id; // the master mixer controls the VUs for recordings (no personal controls in either master or personal mode)
+            trackData.muteMixerId = mixer.id; // the master mixer controls the mute for recordings (no personal controls in either master or personal mode)
+
+            if(sessionModel.isPersonalMixMode() || !isOpener) {
+              //trackData.mediaControlsDisabled = true;
+              trackData.mediaTrackOpener = isOpener;
+            }
+
+            _addRecordingTrack(trackData, mixer);
+          }// if
+          setFormFromMetronome()
         }
 
 
         function renderRecordingTracks(recordingMixers) {
           // get the server's info for the recording
           var recordedTracks = sessionModel.recordedTracks();
+          var recordedBackingTracks = sessionModel.recordedBackingTracks();
 
           // pluck the 1st mixer, and assume that all other mixers in this group are of the same type (between Local vs Peer)
           // if it's a locally opened track (MediaTrackGroup), then we can say this person is the opener
@@ -998,6 +1257,7 @@
           if(recordedTracks) {
             $('.session-recording-name').text(sessionModel.getCurrentSession().claimed_recording.name);
 
+            console.log("renderRecordingTracks", recordingMixers, recordedTracks)
             var noCorrespondingTracks = false;
             $.each(recordingMixers, function(index, mixer) {
               var preMasteredClass = "";
@@ -1023,6 +1283,7 @@
 
               if(correspondingTracks.length == 0) {
                 noCorrespondingTracks = true;
+                logger.debug("unable to correlate all recorded tracks", recordingMixers, recordedTracks)
                 app.notify({
                   title: "Unable to Open Recording",
                   text: "Could not correlate server and client tracks",
@@ -1075,7 +1336,7 @@
                 trackData.mediaControlsDisabled = true;
                 trackData.mediaTrackOpener = isOpener;
               }
-              _addRecordingTrack(trackData);
+              _addRecordingTrack(trackData, mixer);
             });
 
             if(!noCorrespondingTracks && recordedTracks.length > 0) {
@@ -1132,6 +1393,7 @@
 
           var mixMode = sessionModel.getMixMode();
           if(myTrack) {
+
             // when it's your track, look it up by the backend resource ID
             mixer = getMixerByTrackId(track.client_track_id, mixMode)
             vuMixer = mixer;
@@ -1312,16 +1574,35 @@
             }
             var $track = $(trackSelector);
             // Set mixer-id attributes and render VU/Fader
-            context.JK.VuHelpers.renderVU(vuLeftSelector, vuOpts);
-            $track.find('.track-vu-left').attr('mixer-id', track.vuMixerId + '_vul').data('groupId', groupId)
-            context.JK.VuHelpers.renderVU(vuRightSelector, vuOpts);
-            $track.find('.track-vu-right').attr('mixer-id', track.vuMixerId + '_vur').data('groupId', groupId)
+                
+            if (!track.hideVU) {                
+                context.JK.VuHelpers.renderVU(vuLeftSelector, vuOpts);
+                $track.find('.track-vu-left').attr('mixer-id', track.vuMixerId + '_vul').data('groupId', groupId)
+                context.JK.VuHelpers.renderVU(vuRightSelector, vuOpts);
+                $track.find('.track-vu-right').attr('mixer-id', track.vuMixerId + '_vur').data('groupId', groupId)
+            }
+
+            if (track.showMetronomeControls) {
+                $track.find('.metronome-selects').removeClass("hidden")                                
+            } else {
+                $track.find('.metronome-selects').addClass("hidden")                
+            }
+
+            // if (track.showMetroSound) {
+            //     $track.find('.metro-sound-select').removeClass("hidden")
+            // }
+
             context.JK.FaderHelpers.renderFader($fader, faderOpts);
             // Set gain position
             context.JK.FaderHelpers.setFaderValue(mixerId, gainPercent);
-            $fader.on('fader_change', faderChanged);
 
-          return $track;
+            if(track.faderChanged) {
+                $fader.on('fader_change', track.faderChanged);    
+            } else {
+                $fader.on('fader_change', faderChanged);    
+            }
+            
+            return $track;
         }
 
         // Function called on an interval when participants change. Mixers seem to
@@ -1470,13 +1751,10 @@
 
 
 
-        function _addRecordingTrack(trackData) {
+        function _addRecordingTrack(trackData, mixer) {
             var parentSelector = '#session-recordedtracks-container';
             var $destination = $(parentSelector);
-            $('.session-recordings .when-empty').hide();
-            $('.session-recording-name-wrapper').show();
-            $('.session-recordings .recording-controls').show();
-
+            
             var template = $('#template-session-track').html();
             var newTrack = $(context.JK.fillTemplate(template, trackData));
             $destination.append(newTrack);
@@ -1492,6 +1770,22 @@
             if(trackData.mediaControlsDisabled) {
               $trackIconMute.data('media-controls-disabled', true).data('media-track-opener', trackData.mediaTrackOpener)
             }
+            $trackIconMute.data('mixer', mixer).data('opposite-mixer', null)
+
+
+            if(trackData.showLoop) {
+                var $trackIconLoop = $track.find('.track-icon-loop')
+                var $trackIconLoopCheckbox = $trackIconLoop.find('input')
+
+                context.JK.checkbox($trackIconLoopCheckbox)
+                $trackIconLoopCheckbox.on('ifChanged', function() {
+                  var loop = $trackIconLoopCheckbox.is(':checked')
+                  logger.debug("Looping: ", loop, trackData.filename);
+                  context.jamClient.SessionSetBackingTrackFileLoop(trackData.filename, loop)
+                });
+              $trackIconLoop.show()
+            }
+
             // is this used?
             tracks[trackData.trackId] = new context.JK.SessionTrack(trackData.clientId);
         }
@@ -1517,6 +1811,28 @@
             });
         }
 
+        // function tempoFaderChanged(e, data) {
+        //     var $target =  $(this);
+        //     var faderId = $target.attr('mixer-id');
+        //     var groupId = $target.data('groupId');
+        //     var mixerIds = faderId.split(',');
+        //     $.each(mixerIds, function(i,v) {
+        //         // TODO Interpolate tempo values if we decide to go this way:
+        //         if(groupId == ChannelGroupIds.UserMusicInputGroup) {
+        //           // there may be other mixers with this same ID in the case of a Peer Music Stream, so update them as well
+        //         }
+        //     });            
+        // }
+
+        function handleMetronomeCallback(args) {
+            console.log("MetronomeCallback: ", args)
+            metroTempo = args.bpm
+
+            // This isn't actually there, so we rely on the metroSound as set from select on form:
+            // metroSound = args.sound 
+            context.JK.CurrentSessionModel.refreshCurrentSession(true);            
+        }
+
         function handleVolumeChangeCallback(mixerId, isLeft, value, isMuted) {
             // Visually update mixer
             // There is no need to actually set the back-end mixer value as the
@@ -1592,7 +1908,27 @@
             }
           }
 
+        function handleBackingTrackSelectedCallback(result) {
+          if(result.success) {
+            logger.debug("backing track selected: " + result.file);
 
+            rest.openBackingTrack({id: context.JK.CurrentSessionModel.id(), backing_track_path: result.file})
+              .done(function(response) {
+                var openResult = context.jamClient.SessionOpenBackingTrackFile(result.file, false);
+                console.log("BackingTrackPlay response: %o", openResult);
+                //context.JK.CurrentSessionModel.refreshCurrentSession(true);
+                sessionModel.setBackingTrack(result.file);
+              })
+              .fail(function(jqXHR) {
+                app.notifyServerError(jqXHR, "Unable to Open BackingTrack For Playback");
+              })
+
+
+          }
+          else {
+            logger.debug("no backing track selected")
+          }
+        }
         function deleteSession(evt) {
             var sessionId = $(evt.currentTarget).attr("action-id");
             if (sessionId) {
@@ -1911,6 +2247,27 @@
                 .fail(app.ajaxError);
         }
 
+        function openBackingTrack(e) {
+          // just ignore the click if they are currently recording for now
+          if(sessionModel.recordingModel.isRecording()) {
+            app.notify({
+              "title": "Currently Recording",
+              "text": "You can't open a backing track while creating a recording.",
+              "icon_url": "/assets/content/icon_alert_big.png"
+            });
+            return false;
+          }
+
+          context.jamClient.ShowSelectBackingTrackDialog("window.JK.HandleBackingTrackSelectedCallback");
+
+          //app.layout.showDialog('open-backing-track-dialog').one(EVENTS.DIALOG_CLOSED, function(e, data) {
+           // if(!data.cancel && data.result){
+           //   sessionModel.setBackingTrack(data.result);
+           // }
+          //})
+          return false;
+        }
+
         function openJamTrack(e) {
           // just ignore the click if they are currently recording for now
           if(sessionModel.recordingModel.isRecording()) {
@@ -1927,6 +2284,95 @@
           return false;
         }
 
+        function openBackingTrackFile(e) {
+          // just ignore the click if they are currently recording for now
+          if(sessionModel.recordingModel.isRecording()) {
+              app.notify({
+                "title": "Currently Recording",
+                "text": "You can't open a backing track while creating a recording.",
+                "icon_url": "/assets/content/icon_alert_big.png"
+              });
+              return false;
+          } else {
+            context.jamClient.openBackingTrackFile(sessionModel.backing_track)
+            //context.JK.CurrentSessionModel.refreshCurrentSession(true);
+          }
+          return false;
+        }
+
+        function unstableNTPClocks() {
+            var unstable = []
+            
+            // This should be handled in the below loop, actually:
+            // var map = context.jamClient.getMyNetworkState()
+            // if (!map.ntp_stable) {
+            //     unstable.push("self");
+            // }
+
+            var map;
+            $.each(sessionModel.participants(), function(index, participant) {
+                map = context.jamClient.getPeerState(participant.client_id)
+
+                if (!map.ntp_stable) {
+                    var name = participant.user.name;
+                    if (!(name)) {
+                        name = participant.user.first_name + ' ' + participant.user.last_name;
+                    }
+
+                    if (app.clientId == participant.client_id) {
+                        name += " (This computer)"
+                    }
+
+                    unstable.push(name)
+                }
+            });
+   
+            return unstable            
+        }
+
+        function openMetronome(e) {
+          // just ignore the click if they are currently recording for now
+
+          if(sessionModel.recordingModel.isRecording()) {
+              app.notify({
+                "title": "Currently Recording",
+                "text": "You can't open a metronome while creating a recording.",
+                "icon_url": "/assets/content/icon_alert_big.png"
+              });
+              return false;
+          } else {
+            var unstable = unstableNTPClocks()
+            if (unstable.length > 0) {
+                var names = unstable.join(", ")
+                console.log("Unstable clocks: ", names, unstable)
+                app.notify({
+                  "title": "Couldn't open metronome",
+                  "text": "The metronome feature requires that every user's computer in the session must agree on the current time. The computers of " + names + " have not successfully synchronized to the current time.  The JamKazam service is trying to automatically correct this error condition. Please close this message, wait about 10 seconds, and then try opening the metronome again. If this problem persists after a couple of attempts, we recommend that the unsynchronized users restart the JamKazam application. If this error persists after a restart, please have the users with the issue contact support@jamkazam.com.",
+                  "icon_url": "/assets/content/icon_alert_big.png"
+                });
+            } else {
+                rest.openMetronome({id: sessionModel.id()})
+                  .done(function() {
+                    context.jamClient.SessionOpenMetronome(120, "Click", 1, 0)
+                    context.JK.CurrentSessionModel.refreshCurrentSession(true)
+                    context.JK.CurrentSessionModel.refreshCurrentSession(true)
+                  })
+                  .fail(function(jqXHR) {
+                    console.log(jqXHR, jqXHR)
+                    app.notify({
+                      "title": "Couldn't open metronome",
+                      "text": "Couldn't inform the server to open metronome. msg=" + jqXHR.responseText,
+                      "icon_url": "/assets/content/icon_alert_big.png"
+                    });
+                  });
+              }
+
+
+            return false;
+          }
+        }
+
+
         function openRecording(e) {
             // just ignore the click if they are currently recording for now
             if(sessionModel.recordingModel.isRecording()) {
@@ -1952,15 +2398,41 @@
             else if(sessionModel.jamTracks()) {
               closeJamTrack();
             }
-            else {
-              logger.error("don't know how to close open media (backing track?)");
+            else if(sessionModel.backingTrack() && sessionModel.backingTrack().path) {
+              closeBackingTrack();
             }
+            else if(sessionModel.metronomeActive()) {
+              closeMetronomeTrack();
+            }
+            else {
+              logger.error("don't know how to close open media");
+            }
+            return false;
         }
 
+        function closeBackingTrack() {
+          rest.closeBackingTrack({id: sessionModel.id()})
+            .done(function() {
+              //sessionModel.refreshCurrentSession(true);
+            })
+            .fail(function(jqXHR) {
+              app.notify({
+                "title": "Couldn't Close BackingTrack",
+                "text": "Couldn't inform the server to close BackingTrack. msg=" + jqXHR.responseText,
+                "icon_url": "/assets/content/icon_alert_big.png"
+              });
+            });
+
+          // '' closes all open backing tracks
+          context.jamClient.SessionCloseBackingTrackFile('');
+
+          return false;
+        }        
+
         function closeJamTrack() {
           rest.closeJamTrack({id: sessionModel.id()})
             .done(function() {
-              sessionModel.refreshCurrentSession();
+              sessionModel.refreshCurrentSession(true);
             })
             .fail(function(jqXHR) {
               app.notify({
@@ -1975,10 +2447,28 @@
           return false;
         }
 
+        function closeMetronomeTrack() {
+          rest.closeMetronome({id: sessionModel.id()})
+            .done(function() {
+              context.jamClient.SessionCloseMetronome();
+              sessionModel.refreshCurrentSession(true);              
+            })
+            .fail(function(jqXHR) {
+              app.notify({
+                "title": "Couldn't Close MetronomeTrack",
+                "text": "Couldn't inform the server to close MetronomeTrack. msg=" + jqXHR.responseText,
+                "icon_url": "/assets/content/icon_alert_big.png"
+              });
+            });
+          return false;
+        }
+
         function closeRecording() {
             rest.stopPlayClaimedRecording({id: sessionModel.id(), claimed_recording_id: sessionModel.getCurrentSession().claimed_recording.id})
-                .done(function() {
-                    sessionModel.refreshCurrentSession();
+                .done(function(response) {
+                  //sessionModel.refreshCurrentSession(true);
+                  // update session info
+                  context.JK.CurrentSessionModel.updateSession(response);
                 })
                 .fail(function(jqXHR) {
                     app.notify({
@@ -2022,12 +2512,41 @@
                                                                   sessionId);
             inviteMusiciansUtil.loadFriends();
             $(friendInput).show();
-          }
+        }
 
-        function onMixerModeChanged(e, data)
-        {
+        function setFormFromMetronome() {
+            $("select.metro-tempo").val(metroTempo)
+            $("select.metro-sound").val(metroSound)            
+        }
+
+        function setMetronomeFromForm() {
+            var tempo = $("select.metro-tempo:visible option:selected").val()            
+            var sound = $("select.metro-sound:visible option:selected").val()
+
+            var t = parseInt(tempo)
+            var s
+            if (tempo==NaN || tempo==0 || tempo==null) {
+                t = 120
+            }
+
+            if (sound==null || typeof(sound)=='undefined' || sound=="") {
+                s = "click"
+            } else {
+                s = sound
+            }
+
+            console.log("Setting tempo and sound:", t, s)
+            metroTempo = t
+            metroSound = s
+            context.jamClient.SessionSetMetronome(t, s, 1, 0)
+        }
+
+        function onMetronomeChanged(e, data) {
+            setMetronomeFromForm()
+        }
+
+        function onMixerModeChanged(e, data) {
           $mixModeDropdown.easyDropDown('select', data.mode, true);
-
           setTimeout(renderSession, 1);
         }
 
@@ -2046,7 +2565,7 @@
           return true;
         }
 
-        function events() {
+        function events() {            
             $('#session-leave').on('click', sessionLeave);
             $('#session-resync').on('click', sessionResync);
             $('#session-contents').on("click", '[action="delete"]', deleteSession);
@@ -2054,6 +2573,8 @@
             $('#recording-start-stop').on('click', startStopRecording);
             $('#open-a-recording').on('click', openRecording);
             $('#open-a-jamtrack').on('click', openJamTrack);
+            $('#open-a-backingtrack').on('click', openBackingTrack);
+            $('#open-a-metronome').on('click', openMetronome);
             $('#session-invite-musicians').on('click', inviteMusicians);
             $('#session-invite-musicians2').on('click', inviteMusicians);
             $('#track-settings').click(function() {
@@ -2070,6 +2591,7 @@
             $(friendInput).focus(function() { $(this).val(''); })
             $(document).on(EVENTS.MIXER_MODE_CHANGED, onMixerModeChanged)
             $mixModeDropdown.change(onUserChangeMixMode)
+            $(document).on("change", ".metronome-select", onMetronomeChanged)
         }
 
         this.initialize = function(localRecordingsDialogInstance, recordingFinishedDialogInstance, friendSelectorDialog) {
@@ -2080,6 +2602,7 @@
             context.jamClient.SetVURefreshRate(150);
             context.jamClient.RegisterVolChangeCallBack("JK.HandleVolumeChangeCallback");
             playbackControls = new context.JK.PlaybackControls($('.session-recordings .recording-controls'));
+            context.jamClient.setMetronomeOpenCallback("JK.HandleMetronomeCallback")
 
             var screenBindings = {
                 'beforeShow': beforeShow,
@@ -2121,7 +2644,9 @@
         }
 
         context.JK.HandleVolumeChangeCallback = handleVolumeChangeCallback;
+        context.JK.HandleMetronomeCallback = handleMetronomeCallback;        
         context.JK.HandleBridgeCallback = handleBridgeCallback;
+        context.JK.HandleBackingTrackSelectedCallback = handleBackingTrackSelectedCallback;
     };
 
  })(window,jQuery);

web/app/assets/javascripts/sessionModel.js

@@ -34,6 +34,8 @@
         var sessionPageEnterTimeout = null;
         var startTime = null;
         var joinDeferred = null;
+        var previousBackingTracks = [];
+        var openBackingTrack = null;
 
         var mixerMode = MIX_MODES.PERSONAL;
 
@@ -67,7 +69,7 @@
         function isPlayingRecording() {
             // this is the server's state; there is no guarantee that the local tracks
             // requested from the backend will have corresponding track information
-            return currentSession && currentSession.claimed_recording;
+            return !!(currentSession && currentSession.claimed_recording);
         }
 
         function recordedTracks() {
@@ -79,6 +81,28 @@
             }
         }
 
+        function recordedBackingTracks() {
+          if(currentSession && currentSession.claimed_recording) {
+            return currentSession.claimed_recording.recording.recorded_backing_tracks
+          }
+          else {
+            return null;
+          }
+        }
+
+        function backingTracks() {
+          var backingTracks = []
+          // this may be wrong if we loosen the idea that only one person can have a backing track open.
+          // but for now, the 1st person we find with a backing track open is all there is to find...
+          context._.each(participants(), function(participant) {
+            if(participant.backing_tracks.length > 0) {
+              backingTracks = participant.backing_tracks;
+              return false; // break
+            }
+          })
+          return backingTracks;
+        }
+
         function jamTracks() {
           if(currentSession && currentSession.jam_track) {
             return currentSession.jam_track.tracks
@@ -88,6 +112,27 @@
           }
         }
 
+        function backingTrack() {
+          if(currentSession) {
+            // TODO: objectize this for VRFS-2665, VRFS-2666, VRFS-2667, VRFS-2668
+            return {
+              path: currentSession.backing_track_path
+            }
+          }
+          else {
+            return null;
+          }
+        }
+
+        function metronomeActive() {
+          if(currentSession) {
+            return currentSession.metronome_active
+          }
+          else {
+            return null;
+          }
+        }
+
         function creatorId() {
             if(!currentSession) {
                 throw "creator is not known"
@@ -303,6 +348,8 @@
           }
           currentSessionId = null;
           currentParticipants = {}
+          previousBackingTracks = []
+          openBackingTrack = null
         }
 
         // you should only update currentSession with this function
@@ -321,6 +368,25 @@
             }
         }
 
+        function updateSession(response) {
+          updateSessionInfo(response, null, true);
+        }
+
+        function updateSessionInfo(response, callback, force) {
+          if(force === true || currentTrackChanges < response.track_changes_counter) {
+            logger.debug("updating current track changes from %o to %o", currentTrackChanges, response.track_changes_counter)
+            currentTrackChanges = response.track_changes_counter;
+            sendClientParticipantChanges(currentSession, response);
+            updateCurrentSession(response);
+            if(callback != null) {
+              callback();
+            }
+          }
+          else {
+            logger.info("ignoring refresh because we already have current: " + currentTrackChanges + ", seen: " + response.track_changes_counter);
+          }
+        }
+
         /**
         * Reload the session data from the REST server, calling
         * the provided callback when complete.
@@ -344,18 +410,7 @@
                     type: "GET",
                     url: url,
                     success: function(response) {
-                        if(force === true || currentTrackChanges < response.track_changes_counter) {
-                          logger.debug("updating current track changes from %o to %o", currentTrackChanges, response.track_changes_counter)
-                          currentTrackChanges = response.track_changes_counter;
-                          sendClientParticipantChanges(currentSession, response);
-                          updateCurrentSession(response);
-                          if(callback != null) {
-                            callback();
-                          }
-                        }
-                        else {
-                          logger.info("ignoring refresh because we already have current: " + currentTrackChanges + ", seen: " + response.track_changes_counter);
-                        }
+                        updateSessionInfo(response, callback, force);
                     },
                     error: function(jqXHR) {
                       if(jqXHR.status != 404) {
@@ -536,6 +591,46 @@
         return mixerMode;
       }
 
+        function syncTracks(backingTracks) {
+          // double check that we are in session, since a bunch could have happened since then
+          if(!inSession()) {
+            logger.debug("dropping queued up sync tracks because no longer in session");
+            return null;
+          }
+
+          // this is a local change to our tracks.  we need to tell the server about our updated track information
+          var inputTracks = context.JK.TrackHelpers.getUserTracks(context.jamClient);
+
+          // backingTracks can be passed in as an optimization, so that we don't hit the backend excessively
+          if(backingTracks === undefined  ) {
+              backingTracks = context.JK.TrackHelpers.getBackingTracks(context.jamClient);
+          }
+
+          // create a trackSync request based on backend data
+          var syncTrackRequest = {};
+          syncTrackRequest.client_id = app.clientId;
+          syncTrackRequest.tracks = inputTracks;
+          syncTrackRequest.backing_tracks = backingTracks;
+          syncTrackRequest.id = id();
+
+          return rest.putTrackSyncChange(syncTrackRequest)
+            .done(function() {
+            })
+            .fail(function(jqXHR) {
+              if(jqXHR.status != 404) {
+                app.notify({
+                  "title": "Can't Sync Local Tracks",
+                  "text": "The client is unable to sync local track information with the server.  You should rejoin the session to ensure a good experience.",
+                  "icon_url": "/assets/content/icon_alert_big.png"
+                });
+              }
+              else {
+                logger.debug("Unable to sync local tracks because session is gone.")
+              }
+
+            })
+        }
+
         function onWebsocketDisconnected(in_error) {
           // kill the streaming of the session immediately
           if(currentSessionId) {
@@ -678,45 +773,25 @@
               // wait until we are fully in session before trying to sync tracks to server
               if(joinDeferred) {
                 joinDeferred.done(function() {
-
-                  // double check that we are in session, since a bunch could have happened since then
-                  if(!inSession()) {
-                    logger.debug("dropping queued up sync tracks because no longer in session");
-                    return;
-                  }
-
-                  // this is a local change to our tracks.  we need to tell the server about our updated track information
-                  var inputTracks = context.JK.TrackHelpers.getUserTracks(context.jamClient);
-
-                  // create a trackSync request based on backend data
-                  var syncTrackRequest = {};
-                  syncTrackRequest.client_id = app.clientId;
-                  syncTrackRequest.tracks = inputTracks;
-                  syncTrackRequest.id = id();
-
-                  rest.putTrackSyncChange(syncTrackRequest)
-                    .done(function() {
-                    })
-                    .fail(function(jqXHR) {
-                      if(jqXHR.status != 404) {
-                        app.notify({
-                          "title": "Can't Sync Local Tracks",
-                          "text": "The client is unable to sync local track information with the server.  You should rejoin the session to ensure a good experience.",
-                          "icon_url": "/assets/content/icon_alert_big.png"
-                        });
-                      }
-                      else {
-                        logger.debug("Unable to sync local tracks because session is gone.")
-                      }
-
-                    })
+                  syncTracks();
                 })
               }
 
             }, 100);
           }
           else if(inSession() && (text == 'RebuildMediaControl' || text == 'RebuildRemoteUserControl')) {
-            refreshCurrentSession(true);
+
+            var backingTracks = context.JK.TrackHelpers.getBackingTracks(context.jamClient);
+
+            // the way we know if backing tracks changes, or recordings are opened, is via this event.
+            // but we want to report to the user when backing tracks change; so we need to detect change on our own
+            if(previousBackingTracks != backingTracks) {
+              logger.debug("backing tracks changed")
+              syncTracks(backingTracks);
+            }
+            else {
+              refreshCurrentSession(true);
+            }
           }
           else if(inSession() && (text == 'Global Peer Input Mixer Mode')) {
             setMixerMode(MIX_MODES.MASTER);
@@ -729,6 +804,10 @@
         // Public interface
         this.id = id;
         this.start = start;
+        this.backingTrack = backingTrack;
+        this.backingTracks = backingTracks;
+        this.recordedBackingTracks = recordedBackingTracks;
+        this.metronomeActive = metronomeActive;
         this.setUserTracks = setUserTracks;
         this.recordedTracks = recordedTracks;
         this.jamTracks = jamTracks;
@@ -736,6 +815,7 @@
         this.joinSession = joinSession;
         this.leaveCurrentSession = leaveCurrentSession;
         this.refreshCurrentSession = refreshCurrentSession;
+        this.updateSession = updateSession;
         this.subscribe = subscribe;
         this.participantForClientId = participantForClientId;
         this.isPlayingRecording = isPlayingRecording;
@@ -767,6 +847,12 @@
         this.getParticipant = function(clientId) {
             return participantsEverSeen[clientId]
         };
+        this.setBackingTrack = function(backingTrack) {
+          openBackingTrack = backingTrack;
+        };
+        this.getBackingTrack = function() {
+          return openBackingTrack;
+        };
 
         // call to report if the current user was able to establish audio with the specified clientID
         this.setAudioEstablished = function(clientId, audioEstablished) {

web/app/assets/javascripts/sync_viewer.js.coffee

@@ -27,16 +27,19 @@ context.JK.SyncViewer = class SyncViewer
     @list = @root.find('.list')
     @logList = @root.find('.log-list')
     @templateRecordedTrack = $('#template-sync-viewer-recorded-track')
+    @templateRecordedBackingTrack = $('#template-sync-viewer-recorded-backing-track')
     @templateStreamMix = $('#template-sync-viewer-stream-mix')
     @templateMix = $('#template-sync-viewer-mix')
     @templateNoSyncs = $('#template-sync-viewer-no-syncs')
     @templateRecordingWrapperDetails = $('#template-sync-viewer-recording-wrapper-details')
     @templateHoverRecordedTrack = $('#template-sync-viewer-hover-recorded-track')
+    @templateHoverRecordedBackingTrack = $('#template-sync-viewer-hover-recorded-backing-track')
     @templateHoverMix = $('#template-sync-viewer-hover-mix')
     @templateDownloadReset = $('#template-sync-viewer-download-progress-reset')
     @templateUploadReset = $('#template-sync-viewer-upload-progress-reset')
     @templateGenericCommand = $('#template-sync-viewer-generic-command')
     @templateRecordedTrackCommand = $('#template-sync-viewer-recorded-track-command')
+    @templateRecordedBackingTrackCommand = $('#template-sync-viewer-recorded-backing-track-command')
     @templateLogItem = $('#template-sync-viewer-log-item')
     @tabSelectors = @root.find('.dialog-tabs .tab')
     @tabs = @root.find('.tab-content')
@@ -50,7 +53,8 @@ context.JK.SyncViewer = class SyncViewer
       them_upload_soon: 'them-upload-soon'
       missing: 'missing',
       me_uploaded: 'me-uploaded',
-      them_uploaded: 'them-uploaded'
+      them_uploaded: 'them-uploaded',
+      not_mine: 'not-mine'
     }
     @clientStates = {
       unknown: 'unknown',
@@ -58,7 +62,8 @@ context.JK.SyncViewer = class SyncViewer
       hq: 'hq',
       sq: 'sq',
       missing: 'missing',
-      discarded: 'discarded'
+      discarded: 'discarded',
+      not_mine: 'not-mine'
     }
 
     throw "no sync-viewer" if not @root.exists()
@@ -329,12 +334,138 @@ context.JK.SyncViewer = class SyncViewer
       $clientRetry.hide()
       $uploadRetry.hide()
 
+  updateBackingTrackState: ($track) =>
+    clientInfo = $track.data('client-info')
+    serverInfo = $track.data('server-info')
+    myTrack = serverInfo.user.id == context.JK.currentUserId
+
+    # determine client state
+    clientStateMsg = 'UNKNOWN'
+    clientStateClass = 'unknown'
+    clientState = @clientStates.unknown
+
+    if serverInfo.mine
+      if serverInfo.download.should_download
+        if serverInfo.download.too_many_downloads
+          clientStateMsg = 'EXCESS DOWNLOADS'
+          clientStateClass = 'error'
+          clientState = @clientStates.too_many_uploads
+        else
+          if clientInfo?
+            if clientInfo.local_state == 'HQ'
+              clientStateMsg = 'HIGHEST QUALITY'
+              clientStateClass = 'hq'
+              clientState = @clientStates.hq
+            else if clientInfo.local_state == 'MISSING'
+              clientStateMsg = 'MISSING'
+              clientStateClass = 'missing'
+              clientState = @clientStates.missing
+          else
+            clientStateMsg = 'MISSING'
+            clientStateClass = 'missing'
+            clientState = @clientStates.missing
+      else
+        clientStateMsg = 'DISCARDED'
+        clientStateClass = 'discarded'
+        clientState = @clientStates.discarded
+    else
+      clientStateMsg = 'NOT MINE'
+      clientStateClass = 'not_mine'
+      clientState = @clientStates.not_mine
+
+    # determine upload state
+    uploadStateMsg = 'UNKNOWN'
+    uploadStateClass = 'unknown'
+    uploadState = @uploadStates.unknown
+
+    if serverInfo.mine
+      if !serverInfo.fully_uploaded
+        if serverInfo.upload.too_many_upload_failures
+          uploadStateMsg = 'UPLOAD FAILURE'
+          uploadStateClass = 'error'
+          uploadState = @uploadStates.too_many_upload_failures
+        else
+          if myTrack
+            if clientInfo?
+              if clientInfo.local_state == 'HQ'
+                uploadStateMsg = 'PENDING UPLOAD'
+                uploadStateClass = 'upload-soon'
+                uploadState = @uploadStates.me_upload_soon
+              else
+                uploadStateMsg = 'MISSING'
+                uploadStateClass = 'missing'
+                uploadState = @uploadStates.missing
+            else
+              uploadStateMsg = 'MISSING'
+              uploadStateClass = 'missing'
+              uploadState = @uploadStates.missing
+          else
+            uploadStateMsg = 'PENDING UPLOAD'
+            uploadStateClass = 'upload-soon'
+            uploadState = @uploadStates.them_upload_soon
+      else
+        uploadStateMsg = 'UPLOADED'
+        uploadStateClass = 'uploaded'
+        if myTrack
+          uploadState = @uploadStates.me_uploaded
+        else
+          uploadState = @uploadStates.them_uploaded
+    else
+      uploadStateMsg = 'NOT MINE'
+      uploadStateClass = 'not_mine'
+      uploadState = @uploadStates.not_mine
+
+
+    $clientState = $track.find('.client-state')
+    $clientStateMsg = $clientState.find('.msg')
+    $clientStateProgress = $clientState.find('.progress')
+    $uploadState = $track.find('.upload-state')
+    $uploadStateMsg = $uploadState.find('.msg')
+    $uploadStateProgress = $uploadState.find('.progress')
+
+    $clientState.removeClass('discarded missing hq unknown error not-mine').addClass(clientStateClass).attr('data-state', clientState).data('custom-class', clientStateClass)
+    $clientStateMsg.text(clientStateMsg)
+    $clientStateProgress.css('width', '0')
+    $uploadState.removeClass('upload-soon error unknown missing uploaded not-mine').addClass(uploadStateClass).attr('data-state', uploadState).data('custom-class', uploadStateClass)
+    $uploadStateMsg.text(uploadStateMsg)
+    $uploadStateProgress.css('width', '0')
+
+    # this allows us to make styling decisions based on the combination of both client and upload state.
+    $track.addClass("clientState-#{clientStateClass}").addClass("uploadState-#{uploadStateClass}")
+
+    $clientRetry = $clientState.find('.retry')
+    $uploadRetry = $uploadState.find('.retry')
+
+    if gon.isNativeClient
+      # handle client state
+
+      # only show RETRY button if you have a SQ or if it's missing,  and it's been uploaded already
+      if (clientState == @clientStates.missing) and (uploadState == @uploadStates.me_uploaded or uploadState == @uploadStates.them_uploaded)
+        $clientRetry.show()
+      else
+        $clientRetry.hide()
+
+      # only show RETRY button if you have the HQ track, it's your track, and the server doesn't yet have it
+      if myTrack and @clientStates.hq and (uploadState == @uploadStates.error or uploadState == @uploadStates.me_upload_soon)
+        $uploadRetry.show()
+      else
+        $uploadRetry.hide()
+    else
+      $clientRetry.hide()
+      $uploadRetry.hide()
+
+
   associateClientInfo: (recording) =>
     for clientInfo in recording.local_tracks
       $track = @list.find(".recorded-track[data-recording-id='#{recording.recording_id}'][data-client-track-id='#{clientInfo.client_track_id}']")
       $track.data('client-info', clientInfo)
       $track.data('total-size', recording.size)
 
+    for clientInfo in recording.backing_tracks
+      $track = @list.find(".recorded-backing-track[data-recording-id='#{recording.recording_id}'][data-client-track-id='#{clientInfo.client_track_id}']")
+      $track.data('client-info', clientInfo)
+      $track.data('total-size', recording.size)
+
     $track = @list.find(".mix[data-recording-id='#{recording.recording_id}']")
     $track.data('client-info', recording.mix)
     $track.data('total-size', recording.size)
@@ -457,11 +588,77 @@ context.JK.SyncViewer = class SyncViewer
     uploadStateClass: uploadStateClass}
     {variable: 'data'})
 
-  onHoverOfStateIndicator: () ->
+  displayBackingTrackHover: ($recordedTrack) =>
+    $clientState = $recordedTrack.find('.client-state')
+    $clientStateMsg = $clientState.find('.msg')
+    clientStateClass = $clientState.data('custom-class')
+    clientState = $clientState.attr('data-state')
+    clientInfo = $recordedTrack.data('client-info')
+
+    $uploadState = $recordedTrack.find('.upload-state')
+    $uploadStateMsg = $uploadState.find('.msg')
+    uploadStateClass = $uploadState.data('custom-class')
+    uploadState = $uploadState.attr('data-state')
+    serverInfo = $recordedTrack.data('server-info')
+
+    # decide on special case strings first
+
+    summary = ''
+    if clientState == @clientStates.not_mine && @uploadStates.them_uploaded
+      # this is not our backing track
+      summary = "#{serverInfo.user.name} opened this backing track.  Due to legal concerns, we can not distribute it to you."
+    else if clientState == @clientStates.not_mine && @uploadStates.them_upload_soon
+      # this is not our backing track
+      summary = "#{serverInfo.user.name} has not yet uploaded their backing track."
+    else if clientState == @clientStates.missing && uploadState == @uploadStates.me_uploaded
+      # we have no version of the track at all, and the other user has uploaded the HQ version... it's coming soon!
+      summary = "You have previously uploaded the high-quality version of this track.  JamKazam will soon restore it and then this backing track will no longer be missing."
+    else if clientState == @clientStates.discarded && (uploadState == @uploadStates.me_uploaded or uploadState == @uploadStates.them_uploaded)
+      # we decided not to keep the recording... so it's important to clarify why they are seeing it at all
+      summary = "When this recording was made, you elected to not keep it. JamKazam already uploaded your high-quality backing track for the recording, because at least one other person decided to keep the recording and needs your backing track to make a high-quality mix."
+    else if clientState == @clientStates.discarded
+      # we decided not to keep the recording... so it's important to clarify why they are seeing it at all
+      summary = "When this recording was made, you elected to not keep it.  JamKazam will still try to upload your high-quality backing track for the recording, because at least one other person decided to keep the recording and needs your backing track to make a high-quality mix."
+    else if clientState == @clientStates.hq and ( uploadState == @uploadStates.me_uploaded )
+      summary = "Both you and the JamKazam server have the high-quality version of this track.  Once all the other tracks for this recording are also synchronized, then the final mix can be made."
+
+    clientStateDefinition = switch clientState
+      when @clientStates.too_many_downloads then "This backing track has been downloaded an unusually large number of times. No more downloads are allowed."
+      when @clientStates.hq then "HIGHEST QUALITY means you have the original version of this backing track."
+      when @clientStates.missing then "MISSING means you do not have this backing track anymore."
+      when @clientStates.discarded then "DISCARDED means you chose to not keep this recording when the recording was over."
+      when @clientStates.not_mine then "NOT MINE means someone else opened and played this backing track."
+      else 'There is no help for this state'
+
+    uploadStateDefinition = switch uploadState
+      when @uploadStates.too_many_upload_failures then "Failed attempts at uploading this backing track has happened an unusually large times.  No more uploads will be attempted."
+      when @uploadStates.me_upload_soon then "PENDING UPLOAD means your JamKazam application will upload this backing track soon."
+      when @uploadStates.them_up_soon then "PENDING UPLOAD means #{serverInfo.user.name} will upload this  backing track soon."
+      when @uploadStates.me_uploaded then "UPLOADED means you have already uploaded this backing track."
+      when @uploadStates.them_uploaded then "UPLOADED means #{serverInfo.user.name} has already uploaded this backing track."
+      when @uploadStates.missing then "MISSING means your JamKazam application does not have this backing track, and the server does not either."
+      when @uploadStates.not_mine then "NOT MINE means someone else opened and played this backing track."
+
+    context._.template(@templateHoverRecordedBackingTrack.html(),
+    {summary: summary,
+    clientStateDefinition: clientStateDefinition,
+    uploadStateDefinition: uploadStateDefinition,
+    clientStateMsg: $clientStateMsg.text(),
+    uploadStateMsg: $uploadStateMsg.text(),
+    clientStateClass: clientStateClass,
+    uploadStateClass: uploadStateClass}
+    {variable: 'data'})
+
+  onTrackHoverOfStateIndicator: () ->
     $recordedTrack = $(this).closest('.recorded-track.sync')
     self = $recordedTrack.data('sync-viewer')
     self.displayTrackHover($recordedTrack)
 
+  onBackingTrackHoverOfStateIndicator: () ->
+    $recordedTrack = $(this).closest('.recorded-backing-track.sync')
+    self = $recordedTrack.data('sync-viewer')
+    self.displayBackingTrackHover($recordedTrack)
+
   onStreamMixHover: () ->
     $streamMix = $(this).closest('.stream-mix.sync')
     self = $streamMix.data('sync-viewer')
@@ -512,6 +709,39 @@ context.JK.SyncViewer = class SyncViewer
 
     return false
 
+  retryDownloadRecordedBackingTrack: (e) =>
+    $retry = $(e.target)
+    $track = $retry.closest('.recorded-backing-track')
+    serverInfo = $track.data('server-info')
+
+    console.log("track serverInfo", $track, serverInfo)
+    this.sendCommand($retry, {
+      type: 'recorded_backing_track',
+      action: 'download'
+      queue: 'download',
+      recording_id: serverInfo.recording_id
+      track_id: serverInfo.client_track_id
+    })
+
+    return false
+
+  retryUploadRecordedBackingTrack: (e) =>
+    $retry = $(e.target)
+    $track = $retry.closest('.recorded-backing-track')
+    serverInfo = $track.data('server-info')
+
+    console.log("track serverInfo", $track, serverInfo)
+
+    this.sendCommand($retry, {
+      type: 'recorded_backing_track',
+      action: 'upload'
+      queue: 'upload',
+      recording_id: serverInfo.recording_id
+      track_id: serverInfo.client_track_id
+    })
+
+    return false
+
   createMix: (userSync) =>
     recordingInfo = null
     if userSync == 'fake'
@@ -548,8 +778,26 @@ context.JK.SyncViewer = class SyncViewer
     $uploadStateRetry.click(this.retryUploadRecordedTrack)
     context.JK.bindHoverEvents($track)
     context.JK.bindInstrumentHover($track, {positions:['top'], shrinkToFit: true});
-    context.JK.hoverBubble($clientState, this.onHoverOfStateIndicator, {width:'450px', closeWhenOthersOpen: true, positions:['left']})
-    context.JK.hoverBubble($uploadState, this.onHoverOfStateIndicator, {width:'450px', closeWhenOthersOpen: true, positions:['right']})
+    context.JK.hoverBubble($clientState, this.onTrackHoverOfStateIndicator, {width:'450px', closeWhenOthersOpen: true, positions:['left']})
+    context.JK.hoverBubble($uploadState, this.onTrackHoverOfStateIndicator, {width:'450px', closeWhenOthersOpen: true, positions:['right']})
+    $clientState.addClass('is-native-client') if gon.isNativeClient
+    $uploadState.addClass('is-native-client') if gon.isNativeClient
+    $track
+
+  createBackingTrack: (userSync) =>
+    $track = $(context._.template(@templateRecordedBackingTrack.html(), userSync, {variable: 'data'}))
+    $track.data('server-info', userSync)
+    $track.data('sync-viewer', this)
+    $clientState = $track.find('.client-state')
+    $uploadState = $track.find('.upload-state')
+    $clientStateRetry = $clientState.find('.retry')
+    $clientStateRetry.click(this.retryDownloadRecordedBackingTrack)
+    $uploadStateRetry = $uploadState.find('.retry')
+    $uploadStateRetry.click(this.retryUploadRecordedBackingTrack)
+    context.JK.bindHoverEvents($track)
+    context.JK.bindInstrumentHover($track, {positions:['top'], shrinkToFit: true});
+    context.JK.hoverBubble($clientState, this.onBackingTrackHoverOfStateIndicator, {width:'450px', closeWhenOthersOpen: true, positions:['left']})
+    context.JK.hoverBubble($uploadState, this.onBackingTrackHoverOfStateIndicator, {width:'450px', closeWhenOthersOpen: true, positions:['right']})
     $clientState.addClass('is-native-client') if gon.isNativeClient
     $uploadState.addClass('is-native-client') if gon.isNativeClient
     $track
@@ -687,6 +935,8 @@ context.JK.SyncViewer = class SyncViewer
       for userSync in response.entries
         if userSync.type == 'recorded_track'
           @list.append(this.createTrack(userSync))
+        if userSync.type == 'recorded_backing_track'
+          @list.append(this.createBackingTrack(userSync))
         else if userSync.type == 'mix'
           @list.append(this.createMix(userSync))
         else if userSync.type == 'stream_mix'
@@ -707,6 +957,8 @@ context.JK.SyncViewer = class SyncViewer
 
       for track in @list.find('.recorded-track.sync')
         this.updateTrackState($(track))
+      for track in @list.find('.recorded-backing-track.sync')
+        this.updateBackingTrackState($(track))
       for streamMix in @list.find('.stream-mix.sync')
         this.updateStreamMixState($(streamMix))
 
@@ -726,6 +978,18 @@ context.JK.SyncViewer = class SyncViewer
       deferred.resolve(matchingTrack.data('server-info'))
       return deferred
 
+  resolveBackingTrack: (commandMetadata) =>
+    recordingId = commandMetadata['recording_id']
+    clientTrackId = commandMetadata['track_id']
+
+    matchingTrack = @list.find(".recorded-backing-track[data-recording-id='#{recordingId}'][data-client-track-id='#{clientTrackId}']")
+    if matchingTrack.length == 0
+      return @rest.getRecordedBackingTrack({recording_id: recordingId, track_id: clientTrackId})
+    else
+      deferred = $.Deferred();
+      deferred.resolve(matchingTrack.data('server-info'))
+      return deferred
+
   renderFullUploadRecordedTrack: (serverInfo) =>
     $track = $(context._.template(@templateRecordedTrackCommand.html(), $.extend(serverInfo, {action:'UPLOADING'}), {variable: 'data'}))
     $busy = @uploadProgress.find('.busy')
@@ -738,6 +1002,18 @@ context.JK.SyncViewer = class SyncViewer
     $busy.empty().append($track)
     @downloadProgress.find('.progress').css('width', '0%')
 
+  renderFullUploadRecordedBackingTrack: (serverInfo) =>
+    $track = $(context._.template(@templateRecordedBackingTrackCommand.html(), $.extend(serverInfo, {action:'UPLOADING'}), {variable: 'data'}))
+    $busy = @uploadProgress.find('.busy')
+    $busy.empty().append($track)
+    @uploadProgress.find('.progress').css('width', '0%')
+
+  renderFullDownloadRecordedBackingTrack: (serverInfo) =>
+    $track = $(context._.template(@templateRecordedBackingTrackCommand.html(), $.extend(serverInfo, {action:'DOWNLOADING'}), {variable: 'data'}))
+    $busy = @downloadProgress.find('.busy')
+    $busy.empty().append($track)
+    @downloadProgress.find('.progress').css('width', '0%')
+
   # this will either show a generic placeholder, or immediately show the whole track
   renderDownloadRecordedTrack: (commandId, commandMetadata) =>
     # try to find the info in the list; if we can't find it, then resolve it
@@ -756,6 +1032,23 @@ context.JK.SyncViewer = class SyncViewer
 
     deferred.done(this.renderFullUploadRecordedTrack).fail(()=> @logger.error("unable to fetch recorded_track info") )
 
+  # this will either show a generic placeholder, or immediately show the whole track
+  renderDownloadRecordedBackingTrack: (commandId, commandMetadata) =>
+    # try to find the info in the list; if we can't find it, then resolve it
+    deferred = this.resolveBackingTrack(commandMetadata)
+    if deferred.state() == 'pending'
+      this.renderGeneric(commandId, 'download', commandMetadata)
+
+    deferred.done(this.renderFullDownloadRecordedBackingTrack).fail(()=> @logger.error("unable to fetch recorded_backing_track info") )
+
+  renderUploadRecordedBackingTrack: (commandId, commandMetadata) =>
+    # try to find the info in the list; if we can't find it, then resolve it
+    deferred = this.resolveBackingTrack(commandMetadata)
+    if deferred.state() == 'pending'
+      this.renderGeneric(commandId, 'upload', commandMetadata)
+
+    deferred.done(this.renderFullUploadRecordedBackingTrack).fail(()=> @logger.error("unable to fetch recorded_backing_track info") )
+
   renderGeneric: (commandId, category, commandMetadata) =>
     commandMetadata.displayType = this.displayName(commandMetadata)
 
@@ -794,6 +1087,8 @@ context.JK.SyncViewer = class SyncViewer
       @downloadProgress.addClass('busy')
       if commandMetadata.type == 'recorded_track' and commandMetadata.action == 'download'
         this.renderDownloadRecordedTrack(commandId, commandMetadata)
+      else if commandMetadata.type == 'recorded_backing_track' and commandMetadata.action == 'download'
+        this.renderDownloadRecordedBackingTrack(commandId, commandMetadata)
       else
         this.renderGeneric(commandId, 'download', commandMetadata)
     else if commandMetadata.queue == 'upload'
@@ -803,6 +1098,8 @@ context.JK.SyncViewer = class SyncViewer
       @uploadProgress.addClass('busy')
       if commandMetadata.type == 'recorded_track' and commandMetadata.action == 'upload'
         this.renderUploadRecordedTrack(commandId, commandMetadata)
+      else if commandMetadata.type == 'recorded_backing_track' and commandMetadata.action == 'upload'
+        this.renderUploadRecordedBackingTrack(commandId, commandMetadata)
       else
         this.renderGeneric(commandId, 'upload', commandMetadata)
     else if commandMetadata.queue == 'cleanup'
@@ -820,6 +1117,12 @@ context.JK.SyncViewer = class SyncViewer
         $track.data('server-info', userSync)
         this.associateClientInfo(clientRecordings.recordings[0])
         this.updateTrackState($track)
+      else if userSync.type == 'recorded_backing_track'
+        $track = @list.find(".sync[data-id='#{userSync.id}']")
+        continue if $track.length == 0
+        $track.data('server-info', userSync)
+        this.associateClientInfo(clientRecordings.recordings[0])
+        this.updateBackingTrackState($track)
       else if userSync.type == 'mix'
         # check if there is a virtual mix 1st; if so, update it
         $mix = @list.find(".mix.virtual[data-recording-id='#{userSync.recording.id}']")
@@ -839,20 +1142,6 @@ context.JK.SyncViewer = class SyncViewer
   updateSingleRecording: (recording_id) =>
     @rest.getUserSyncs({recording_id: recording_id}).done(this.renderSingleRecording)
 
-  updateSingleRecordedTrack: ($track) =>
-    serverInfo = $track.data('server-info')
-    @rest.getUserSync({user_sync_id: serverInfo.id})
-      .done((userSync) =>
-        # associate new server-info with this track
-        $track.data('server-info', userSync)
-        # associate new client-info with this track
-        clientRecordings = context.jamClient.GetLocalRecordingState(recordings: [userSync.recording])
-        this.associateClientInfo(clientRecordings.recordings[0])
-
-        this.updateTrackState($track)
-      )
-      .fail(@app.ajaxError)
-
   updateProgressOnSync: ($track, queue, percentage) =>
     state = if queue == 'upload' then '.upload-state' else '.client-state'
     $progress = $track.find("#{state} .progress")
@@ -892,10 +1181,10 @@ context.JK.SyncViewer = class SyncViewer
       $progress = @downloadProgress.find('.progress')
       $progress.css('width', percentage + '%')
 
-      if @downloadMetadata.type == 'recorded_track'
+      if @downloadMetadata.type == 'recorded_track' or @downloadMetadata.type == 'recorded_backing_track'
         clientTrackId = @downloadMetadata['track_id']
         recordingId = @downloadMetadata['recording_id']
-        $matchingTrack = @list.find(".recorded-track.sync[data-recording-id='#{recordingId}'][data-client-track-id='#{clientTrackId}']")
+        $matchingTrack = @list.find(".track-item.sync[data-recording-id='#{recordingId}'][data-client-track-id='#{clientTrackId}']")
         if $matchingTrack.length > 0
           this.updateProgressOnSync($matchingTrack, 'download', percentage)
 
@@ -903,10 +1192,10 @@ context.JK.SyncViewer = class SyncViewer
       $progress = @uploadProgress.find('.progress')
       $progress.css('width', percentage + '%')
 
-      if @uploadMetadata.type == 'recorded_track' and @uploadMetadata.action == 'upload'
+      if (@uploadMetadata.type == 'recorded_track' or @uploadMetadata.type == 'recorded_backing_track') and @uploadMetadata.action == 'upload'
         clientTrackId = @uploadMetadata['track_id']
         recordingId = @uploadMetadata['recording_id']
-        $matchingTrack = @list.find(".recorded-track.sync[data-recording-id='#{recordingId}'][data-client-track-id='#{clientTrackId}']")
+        $matchingTrack = @list.find(".track-item.sync[data-recording-id='#{recordingId}'][data-client-track-id='#{clientTrackId}']")
         if $matchingTrack.length > 0
           this.updateProgressOnSync($matchingTrack, 'upload', percentage)
       else if @uploadMetadata.type == 'stream_mix' and @uploadMetadata.action == 'upload'
@@ -977,15 +1266,15 @@ context.JK.SyncViewer = class SyncViewer
     this.logResult(data.commandMetadata, false, data.commandReason, true)
 
   displayName: (metadata) =>
-    if metadata.type == 'recorded_track' && metadata.action == 'download'
+    if (metadata.type == 'recorded_track' || metadata.type == 'recorded_backing_track') && metadata.action == 'download'
       return 'DOWNLOADING TRACK'
-    else if metadata.type == 'recorded_track' && metadata.action == 'upload'
+    else if (metadata.type == 'recorded_track' || metadata.type == 'recorded_backing_track') && metadata.action == 'upload'
       return 'UPLOADING TRACK'
     else if metadata.type == 'mix' && metadata.action == 'download'
       return 'DOWNLOADING MIX'
-    else if metadata.type == 'recorded_track' && metadata.action == 'convert'
+    else if (metadata.type == 'recorded_track' || metadata.type == 'recorded_backing_track') && metadata.action == 'convert'
       return 'COMPRESSING TRACK'
-    else if metadata.type == 'recorded_track' && metadata.action == 'delete'
+    else if (metadata.type == 'recorded_track' || metadata.type == 'recorded_backing_track') && metadata.action == 'delete'
       return 'CLEANUP TRACK'
     else if metadata.type == 'stream_mix' && metadata.action == 'upload'
       return 'UPLOADING STREAM MIX'

web/app/assets/javascripts/trackHelpers.js

@@ -30,6 +30,28 @@
             return tracks;
         },
 
+        getBackingTracks: function(jamClient) {
+            var mediaTracks  = context.JK.TrackHelpers.getTracks(jamClient, 4);
+
+            console.log("mediaTracks", mediaTracks)
+
+            var backingTracks = []
+            context._.each(mediaTracks, function(mediaTrack) {
+                // the check for 'not managed' means this is not a track opened by a recording, basically
+                // we do not try and sync these sorts of backing tracks to the server, because they
+                // are already encompassed by
+                if(mediaTrack.media_type == "BackingTrack" && !mediaTrack.managed) {
+                    var track = {};
+                    track.client_track_id = mediaTrack.persisted_track_id;
+                    track.client_resource_id = mediaTrack.rid;
+                    track.filename = mediaTrack.filename;
+                    backingTracks.push(track);
+                }
+            })
+
+            return backingTracks;
+        },
+
         /**
         * This function resolves which tracks to configure for a user
         * when creating or joining a session. By default, tracks are pulled

web/app/assets/javascripts/utils.js

@@ -987,6 +987,15 @@
     return hasFlash;
   }
 
+  context.JK.getNameOfFile = function(filename) {
+
+    var index = filename.lastIndexOf('/');
+    if(index == -1) {
+      index = filename.lastIndexOf('\\');
+    }
+    return index == -1 ? filename : filename.substring(index + 1, filename.length)
+  }
+
   context.JK.hasOneConfiguredDevice = function () {
     var result = context.jamClient.FTUEGetGoodConfigurationList();
     logger.debug("hasOneConfiguredDevice: ", result);

web/app/assets/stylesheets/client/common.css.scss

@@ -208,6 +208,10 @@ $fair: #cc9900;
       background-color: $error;
     }
 
+    &.not_mine {
+      background-color: $good;
+    }
+
     &.discarded {
       background-color: $unknown;
     }
@@ -252,6 +256,10 @@ $fair: #cc9900;
       background-color: $good;
     }
 
+    &.not_mine {
+      background-color: $good;
+    }
+
     .retry {
       display:none;
       position:absolute;

web/app/assets/stylesheets/client/help.css.scss

@@ -45,7 +45,7 @@ body.jam, body.web, .dialog{
         }
       }
 
-      .help-hover-recorded-tracks, .help-hover-stream-mix {
+      .help-hover-recorded-tracks, .help-hover-stream-mix, .help-hover-recorded-backing-tracks {
 
         font-size:12px;
         padding:5px;

web/app/assets/stylesheets/client/session.css.scss

@@ -18,7 +18,7 @@
 
     .track {
       width:70px;
-      height:290px;
+      height:300px;
       display:inline-block;
       margin-right:8px;
       position:relative;
@@ -50,6 +50,9 @@
       vertical-align:top;
     }
 
+    .session-recordedtracks-container {
+        //display: block;
+    }
 
     .recording-controls {
       display:none;
@@ -74,17 +77,23 @@
       left:5px;
     }
 
-    .open-media-file-header {
+    .open-media-file-header, .use-metronome-header {
         font-size:16px;
         line-height:100%;
         margin:0;
-        float:left;
 
         img {
             position:relative;
             top:3px;
         }
     }
+    .open-media-file-header {
+        float: left;
+    }
+
+    .use-metronome-header {
+        clear: both;
+    }
 
     .open-media-file-options {
         font-size:16px;
@@ -110,8 +119,21 @@
 
     .session-recording-name-wrapper{
         position:relative;
-        white-space:nowrap;
-        display:none;
+        white-space:normal;
+        display:none;     
+           
+        .session-recording-name {
+            position:relative;
+            margin-top:9px;
+            margin-bottom:8px;
+            font-size:16px;
+            height: 22px;
+            min-height: 22px;
+            max-height: 22px;
+            display: inline-block;
+            width:60%;
+            text-overflow:ellipsis;
+        }
 
         .session-add {
             margin-top:9px;
@@ -126,13 +148,6 @@
         }
     }
 
-    .session-recording-name {
-        width:60%;
-        overflow:hidden;
-        margin-top:9px;
-        margin-bottom:8px;
-        font-size:16px;
-    }
 }
 
 
@@ -201,6 +216,9 @@ table.vu td {
     position: absolute;
     text-align:center;
     width: 55px;
+    height: 15px;
+    min-height: 11px;
+    max-height: 33px;
     max-width: 55px;
     white-space:normal;
     top: 3px;
@@ -208,6 +226,7 @@ table.vu td {
     font-family: Arial, Helvetica, sans-serif;
     font-size: 11px;
     font-weight: bold;
+    text-overflow:ellipsis;    
 }
 
 .track-close {
@@ -319,8 +338,6 @@ table.vu td {
     color: inherit;
 }
 
-
-
 .session-add {
     margin-top:9px;
     margin-bottom:8px;
@@ -345,7 +362,7 @@ table.vu td {
     overflow-x:auto;
     overflow-y:hidden;
     width:100%;
-    height:340px;
+    height:370px;
     float:left;
     white-space:nowrap;
 }
@@ -482,7 +499,7 @@ table.vu td {
 .track-gain {
     position:absolute;
     width:28px;
-    height:83px;
+    height:63px;
     top:138px;
     left:23px;
     background-image:url('/assets/content/bkg_gain_slider.png');
@@ -514,6 +531,45 @@ table.vu td {
     height: 18px;
     background-image:url('/assets/content/icon_mute.png');
     background-repeat:no-repeat;
+    text-align: center;
+}
+
+.track-icon-loop {
+    cursor: pointer;
+    position:absolute;
+    top:250px;
+    left:11px;
+    width: 20px;
+    height: 18px;
+    text-align: center;
+    font-size: 8pt;
+    font-weight: bold;
+
+    .icheckbox_minimal {
+      top:5px;
+      margin-right:5px;
+    }
+}
+
+.metronome-selects {
+    position: absolute;
+    width: 52px;
+    top:252px;
+    left: 10px;
+    
+    height: 18px;    
+    text-align: center;
+    //display: block;
+    //padding: 4px;
+
+    select.metronome-select {
+        position: relative;
+        padding: 4px 0px 4px 0px;
+        margin: 0;
+        width: 100% !important;
+        font-size: 10px;
+        font-weight: normal;        
+    }    
 }
 
 .track-icon-mute.muted {
@@ -524,12 +580,12 @@ table.vu td {
 }
 
 .session-livetracks .track-icon-mute, .session-recordings .track-icon-mute {
-    top:245px;
+    top:225px;
 }
 
 .track-icon-settings {
     position:absolute;
-    top:255px;
+    top:235px;
     left:28px;
 }
 

web/app/assets/stylesheets/client/sessionList.css.scss

@@ -1,7 +1,7 @@
 @import "client/common";
 
 
-table.findsession-table, table.local-recordings, table.open-jam-tracks, #account-session-detail {
+table.findsession-table, table.local-recordings, table.open-jam-tracks, table.open-backing-tracks, #account-session-detail {
 
   .latency-unacceptable {
     width: 50px;
@@ -64,7 +64,7 @@ table.findsession-table, table.local-recordings, table.open-jam-tracks, #account
     text-align:center;
   }
 }
-table.findsession-table, table.local-recordings, table.open-jam-tracks {
+table.findsession-table, table.local-recordings, table.open-jam-tracks, table.open-backing-tracks {
   width:98%;
   height:10%;
   font-size:11px;

web/app/assets/stylesheets/dialogs/openBackingTrackDialog.css.scss

@@ -0,0 +1,40 @@
+@import "client/common";
+
+#open-backing-track-dialog {
+  table.open-backing-tracks {
+    tbody {
+      tr:hover {
+        background-color: #777;
+        cursor:pointer;
+      }
+
+      tr[data-local-state=MISSING], tr[data-local-state=PARTIALLY_MISSING] {
+        background-color:#777;
+        color:#aaa;
+      }
+    }
+  }
+
+  .right {
+    margin-right:10px;
+  }
+
+  .help-links {
+    text-align: left;
+    position: absolute;
+    margin: 0 auto;
+    width: 70%;
+    //left: 15%;
+    font-size: 12px;
+    padding-top:5px;
+
+    a {
+      margin:0 10px;
+    }
+  }
+
+  .paginator-holder {
+    padding-top:3px;
+  }
+}
+

web/app/controllers/api_backing_tracks_controller.rb

@@ -0,0 +1,32 @@
+class ApiBackingTracksController < ApiController
+
+  # have to be signed in currently to see this screen
+  before_filter :api_signed_in_user
+
+  before_filter :lookup_recorded_backing_track, :only => [ :backing_track_silent ]
+  
+  respond_to :json
+
+  def index    
+    tracks = [
+      {:name=>'foo',:path=>"foobar.mp3", :length=>4283},
+      {:name=>'bar',:path=>"foo.mp3",:length=>3257}
+    ]
+    @backing_tracks, @next = tracks, nil
+    render "api_backing_tracks/index", :layout => nil    
+  end
+
+  def backing_track_silent
+    @recorded_backing_track.mark_silent
+
+    render :json => {}, :status => 200
+  end
+
+  private
+
+  def lookup_recorded_backing_track
+    @recorded_backing_track = RecordedBackingTrack.find_by_recording_id_and_client_track_id!(params[:id], params[:track_id])
+    raise PermissionError, ValidationMessages::PERMISSION_VALIDATION_ERROR unless @recorded_backing_track.recording.has_access?(current_user)
+  end
+
+end # class ApiBackingTracksController

web/app/controllers/api_music_sessions_controller.rb

@@ -4,7 +4,7 @@ class ApiMusicSessionsController < ApiController
 
   # have to be signed in currently to see this screen
   before_filter :api_signed_in_user, :except => [ :add_like, :show, :show_history, :add_session_info_comment ]
-  before_filter :lookup_session,   only: [:show, :update, :delete, :claimed_recording_start, :claimed_recording_stop, :track_sync, :jam_track_open, :jam_track_close]
+  before_filter :lookup_session,   only: [:show, :update, :delete, :claimed_recording_start, :claimed_recording_stop, :track_sync, :jam_track_open, :jam_track_close, :backing_track_open, :backing_track_close, :metronome_open, :metronome_close]
   skip_before_filter :api_signed_in_user, only: [:perf_upload]
 
   respond_to :json
@@ -357,7 +357,7 @@ class ApiMusicSessionsController < ApiController
   end
 
   def track_sync
-    @tracks = MusicSessionManager.new.sync_tracks(@music_session, params[:client_id], params[:tracks])
+    @tracks = MusicSessionManager.new.sync_tracks(@music_session, params[:client_id], params[:tracks], params[:backing_tracks])
 
     unless @tracks.kind_of? Array
       # we have to do this because api_session_detail_url will fail with a bad @tracks
@@ -597,8 +597,44 @@ class ApiMusicSessionsController < ApiController
     respond_with_model(@music_session)
   end
 
+  def backing_track_open
+    unless @music_session.users.exists?(current_user)
+      raise PermissionError, ValidationMessages::PERMISSION_VALIDATION_ERROR
+    end
 
-  private
+    @backing_track_path = params[:backing_track_path]    
+    @music_session.open_backing_track(current_user, @backing_track_path)
+    respond_with_model(@music_session)
+  end
+
+  def backing_track_close
+    unless @music_session.users.exists?(current_user)
+      raise PermissionError, ValidationMessages::PERMISSION_VALIDATION_ERROR
+    end
+
+    @music_session.close_backing_track()
+    respond_with_model(@music_session)
+  end
+
+  def metronome_open
+    unless @music_session.users.exists?(current_user)
+      raise PermissionError, ValidationMessages::PERMISSION_VALIDATION_ERROR
+    end
+
+    @music_session.open_metronome(current_user)
+    respond_with_model(@music_session)
+  end
+
+  def metronome_close
+    unless @music_session.users.exists?(current_user)
+      raise PermissionError, ValidationMessages::PERMISSION_VALIDATION_ERROR
+    end
+
+    @music_session.close_metronome()
+    respond_with_model(@music_session)
+  end
+
+private
 
   def lookup_session
     @music_session = ActiveMusicSession.find(params[:id])

web/app/controllers/api_recordings_controller.rb

@@ -3,6 +3,7 @@ class ApiRecordingsController < ApiController
 
   before_filter :lookup_recording, :only => [ :show, :stop, :claim, :discard, :keep, :delete_claim ]
   before_filter :lookup_recorded_track, :only => [ :download, :upload_next_part, :upload_sign, :upload_part_complete, :upload_complete ]
+  before_filter :lookup_recorded_backing_track, :only => [ :backing_track_download, :backing_track_upload_next_part, :backing_track_upload_sign, :backing_track_upload_part_complete, :backing_track_upload_complete ]
   before_filter :lookup_recorded_video, :only => [ :video_upload_sign, :video_upload_start, :video_upload_complete ]
   before_filter :lookup_stream_mix, :only => [ :upload_next_part_stream_mix, :upload_sign_stream_mix, :upload_part_complete_stream_mix, :upload_complete_stream_mix ]
 
@@ -43,7 +44,11 @@ class ApiRecordingsController < ApiController
     @recorded_track = RecordedTrack.find_by_recording_id_and_client_track_id(params[:id], params[:track_id])
   end
 
-  def download
+  def show_recorded_backing_track
+    @recorded_backing_track = RecordedBackingTrack.find_by_recording_id_and_client_track_id(params[:id], params[:track_id])
+  end
+
+  def download # track
     raise PermissionError, ValidationMessages::PERMISSION_VALIDATION_ERROR unless @recorded_track.can_download?(current_user)
 
     @recorded_track.current_user = current_user
@@ -58,6 +63,21 @@ class ApiRecordingsController < ApiController
     end
   end
 
+  def backing_track_download
+    raise PermissionError, ValidationMessages::PERMISSION_VALIDATION_ERROR unless @recorded_backing_track.can_download?(current_user)
+
+    @recorded_backing_track.current_user = current_user
+    @recorded_backing_track.update_download_count
+
+    @recorded_backing_track.valid?
+    if !@recorded_backing_track.errors.any?
+      @recorded_backing_track.save!
+      redirect_to @recorded_backing_track.sign_url
+    else
+      render :json => { :message => "download limit surpassed" }, :status => 404
+    end
+  end
+
   def start
     music_session = ActiveMusicSession.find(params[:music_session_id])
 
@@ -227,6 +247,61 @@ class ApiRecordingsController < ApiController
     end
   end
 
+  def backing_track_upload_next_part
+    length = params[:length]
+    md5 = params[:md5]
+
+    @recorded_backing_track.upload_next_part(length, md5)
+
+    if @recorded_backing_track.errors.any?
+
+      response.status = :unprocessable_entity
+      # this is not typical, but please don't change this line unless you are sure it won't break anything
+      # this is needed because after_rollback in the RecordedTrackObserver touches the model and something about it's
+      # state doesn't cause errors to shoot out like normal.
+      render :json => { :errors => @recorded_backing_track.errors }, :status => 422
+    else
+      result = {
+          :part => @recorded_backing_track.next_part_to_upload,
+          :offset => @recorded_backing_track.file_offset.to_s
+      }
+
+      render :json => result, :status => 200
+    end
+
+  end
+
+  def backing_track_upload_sign
+    render :json => @recorded_backing_track.upload_sign(params[:md5]), :status => 200
+  end
+
+  def backing_track_upload_part_complete
+    part = params[:part]
+    offset = params[:offset]
+
+    @recorded_backing_track.upload_part_complete(part, offset)
+
+    if @recorded_backing_track.errors.any?
+      response.status = :unprocessable_entity
+      respond_with @recorded_backing_track
+    else
+      render :json => {}, :status => 200
+    end
+  end
+
+  def backing_track_upload_complete
+    @recorded_backing_track.upload_complete
+    @recorded_backing_track.recording.upload_complete
+
+    if @recorded_backing_track.errors.any?
+      response.status = :unprocessable_entity
+      respond_with @recorded_backing_track
+      return
+    else
+      render :json => {}, :status => 200
+    end
+  end
+
   # POST /api/recordings/:id/videos/:video_id/upload_sign
   def video_upload_sign
     length = params[:length]
@@ -314,6 +389,11 @@ class ApiRecordingsController < ApiController
     raise PermissionError, ValidationMessages::PERMISSION_VALIDATION_ERROR unless @recorded_track.recording.has_access?(current_user)
   end
 
+  def lookup_recorded_backing_track
+    @recorded_backing_track = RecordedBackingTrack.find_by_recording_id_and_client_track_id!(params[:id], params[:track_id])
+    raise PermissionError, ValidationMessages::PERMISSION_VALIDATION_ERROR unless @recorded_backing_track.recording.has_access?(current_user)
+  end
+
   def lookup_stream_mix
     @quick_mix = QuickMix.find_by_recording_id_and_user_id!(params[:id], current_user.id)
     raise PermissionError, ValidationMessages::PERMISSION_VALIDATION_ERROR unless @quick_mix.recording.has_access?(current_user)

web/app/helpers/sessions_helper.rb

@@ -91,4 +91,10 @@ module SessionsHelper
       current_user.musician? ? 'Musician' : 'Fan'
     end
   end
+
+  def metronome_tempos
+    [
+      40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 63, 66, 69, 72, 76, 80, 84, 88, 92, 96, 100, 104, 108, 112, 116, 120, 126, 132, 138, 144, 152, 160, 168, 176, 184, 192, 200, 208
+    ]
+  end
 end

web/app/views/api_backing_tracks/index.rabl

@@ -0,0 +1,7 @@
+node :next do |page|
+    @next
+end
+
+node :backing_tracks do |page|
+  @backing_tracks  
+end

web/app/views/api_claimed_recordings/show.rabl

@@ -2,6 +2,8 @@
 # I don't think I need to include URLs since that's handled by syncing. This is just to make the metadata 
 # depictable.
 
+# THIS IS USED DIRECTLY BY THE CLIENT.  DO NOT CHANGE FORMAT UNLESS YOU VERIFY CLIENT FIRST.  IN PARTICULAR RecordingFileStorage#getLocalRecordingState
+
 object @claimed_recording
 
 attributes :id, :name, :description, :is_public, :genre_id, :discarded
@@ -36,6 +38,18 @@ child(:recording => :recording) {
       }
     }
 
+    child(:recorded_backing_tracks => :recorded_backing_tracks) {
+      attributes :id, :fully_uploaded, :client_track_id, :client_id, :filename
+
+      child(:user => :user) {
+        attributes :id, :first_name, :last_name, :name, :city, :state, :country, :location, :photo_url
+      }
+
+      node :mine do |recorded_backing_track|
+        recorded_backing_track.user == current_user
+      end
+    }
+
     child(:comments => :comments) {
       attributes :comment, :created_at
 

web/app/views/api_music_sessions/show.rabl

@@ -13,7 +13,7 @@ if !current_user
   }
 else
 
-  attributes :id, :name, :description, :musician_access, :approval_required, :fan_access, :fan_chat, :band_id, :user_id, :claimed_recording_initiator_id, :track_changes_counter, :max_score
+  attributes :id, :name, :description, :musician_access, :approval_required, :fan_access, :fan_chat, :band_id, :user_id, :claimed_recording_initiator_id, :track_changes_counter, :max_score, :backing_track_path, :metronome_active
 
   node :can_join do |session|
     session.can_join?(current_user, true)
@@ -54,6 +54,10 @@ else
     child(:tracks => :tracks) {
         attributes :id, :connection_id, :instrument_id, :sound, :client_track_id, :client_resource_id, :updated_at
     }
+
+    child(:backing_tracks => :backing_tracks) {
+        attributes :id, :connection_id, :filename, :client_track_id, :client_resource_id, :updated_at
+    }
   }
 
   child({:invitations => :invitations}) {
@@ -114,6 +118,14 @@ else
                 attributes :id, :first_name, :last_name, :city, :state, :country, :photo_url
               }
           }
+
+          child(:recorded_backing_tracks => :recorded_backing_tracks) {
+              attributes :id, :fully_uploaded, :client_track_id, :client_id, :filename
+
+              child(:user => :user) {
+                attributes :id, :first_name, :last_name, :city, :state, :country, :photo_url
+              }
+          }
       }
   }
 

web/app/views/api_recordings/show.rabl

@@ -27,6 +27,12 @@ child(:recorded_tracks => :recorded_tracks) {
   end
 }
 
+child(:recorded_backing_tracks => :recorded_backing_tracks) {
+  node do |recorded_backing_track|
+    partial("api_recordings/show_recorded_backing_track", :object => recorded_backing_track)
+  end
+}
+
 child(:comments => :comments) {
   attributes :comment, :created_at
 

web/app/views/api_recordings/show_recorded_backing_track.rabl

@@ -0,0 +1,11 @@
+object @recorded_backing_track
+
+attributes :id, :fully_uploaded, :client_track_id, :client_id, :recording_id, :filename
+
+node :mine do |recorded_backing_track|
+    recorded_backing_track.user == current_user
+  end
+
+child(:user => :user) {
+  attributes :id, :first_name, :last_name, :city, :state, :country, :location, :photo_url
+}

web/app/views/api_user_syncs/show.rabl

@@ -18,7 +18,6 @@ glue :recorded_track do
     partial("api_recordings/show", :object => recorded_track.recording)
   end
 
-
   node :upload do |recorded_track|
     {
       should_upload: true,
@@ -35,6 +34,45 @@ glue :recorded_track do
 
 end
 
+
+glue :recorded_backing_track do
+
+  @object.current_user = current_user
+
+  node :type do |i|
+    'recorded_backing_track'
+  end
+
+  attributes :id, :recording_id, :client_id, :track_id, :client_track_id, :md5, :length, :download_count, :fully_uploaded, :upload_failures, :part_failures, :created_at, :filename
+
+  node :user do |recorded_backing_track|
+    partial("api_users/show_minimal", :object => recorded_backing_track.user)
+  end
+
+  node :recording do |recorded_backing_track|
+    partial("api_recordings/show", :object => recorded_backing_track.recording)
+  end
+
+  node :mine do |recorded_backing_track|
+    recorded_backing_track.user == current_user
+  end
+
+  node :upload do |recorded_backing_track|
+    {
+      should_upload: true,
+      too_many_upload_failures: recorded_backing_track.too_many_upload_failures?
+    }
+  end
+
+  node :download do |recorded_backing_track|
+    {
+      should_download: recorded_backing_track.can_download?(current_user),
+      too_many_downloads: recorded_backing_track.too_many_downloads?
+    }
+  end
+
+end
+
 glue :mix do
 
   @object.current_user = current_user

web/app/views/clients/_session.html.erb

@@ -1,199 +0,0 @@
-<!-- Actual Session Screen -->
-<div layout="screen" layout-id="session" layout-arg="id" class="screen secondary" id="session-screen">
-    <div class="content-head">
-        <div class="content-icon">
-            <%= image_tag "shared/icon_session.png", {:height => 19, :width => 19} %>
-        </div>
-        <h1>session</h1>
-    </div>
-
-    <div class="content-body">
-    <!-- session controls -->
-        <div id="session-controls">
-            <a class="button-grey resync left" id="session-resync">
-                <%= image_tag "content/icon_resync.png", {:align => "texttop", :height => 14, :width => 12} %>
-                RESYNC
-            </a>
-            <a class="button-grey left" layout-link="session-settings" id="session-settings-button">
-                <%= image_tag "content/icon_settings_sm.png", {:align => "texttop", :height => 12, :width => 12} %>
-                SETTINGS
-            </a>
-            <a layout-link="share-dialog" class="button-grey left">
-                <%= image_tag "content/icon_share.png", {:align => "texttop", :height => 12, :width => 12} %> 
-                SHARE
-            </a>
-
-            <!-- Volume Slider -->
-            <div class="block">
-                <div class="label">VOLUME:</div>
-                <div id="volume" class="fader lohi" mixer-id=""></div>
-            </div>
-
-            <!-- Mix: Me versus Others -->
-
-            <div class="block monitor-mode-holder">
-              <div class="label">MIX:</div>
-              <select class="monitor-mode easydropdown">
-                <option value="personal" class="label">Personal</option>
-                <option value="master">Master</option>
-              </select>
-            </div>
-          <!--
-            <div class="block">
-                <div class="label">MONITOR:</div>
-                <div class="label"><small>others</small></div>
-                <div id="l2m" class="fader flat" mixer-id="__L2M__"></div>
-                <div class="label"><small>me</small></div>
-            </div>
-            -->
-
-            <!-- Leave Button -->
-            <a class="button-grey right leave" href="/client#/home" id="session-leave">X&nbsp;&nbsp;LEAVE</a>
-        </div>
-        <!-- end session controls -->
-
-        <!-- content scrolling area -->
-        <div id="tracks">
-            <div class="content-scroller">
-
-                <!-- content wrapper -->
-                <div class="content-wrapper">
-
-                    <!-- my tracks -->
-                    <div class="session-mytracks">
-                        <h2>my tracks</h2>
-                        <div id="track-settings" class="session-add" style="display:block;" layout-link="configure-tracks">
-                            <%= image_tag "content/icon_settings_lg.png", {:width => 18, :height => 18} %>
-                          <span>Settings</span>
-                        </div>
-
-                        <div class="session-tracks-scroller">
-                            <div id="session-mytracks-container"></div>
-                            <div id="voice-chat" class="voicechat" style="display:none;" mixer-id="">
-                                <div class="voicechat-label">CHAT</div>
-                                <div class="voicechat-gain"></div>
-                                <div class="voicechat-mute enabled" control="mute" mixer-id=""></div>
-                            </div>
-                        </div>
-                    </div>
-
-                    <!-- live tracks -->
-                    <div class="session-livetracks">
-                        <h2>live tracks</h2>
-                        <div class="session-add" layout-link="select-invites">
-                            <a href="#" id="session-invite-musicians">
-                                <%= image_tag "content/icon_add.png", {:width => 19, :height => 19, :align => "texttop"} %>&nbsp;&nbsp;Invite Musicians
-                            </a>
-                        </div>
-                        <div class="session-tracks-scroller">
-                            <div id="session-livetracks-container">
-                                <div class="when-empty livetracks">
-                                No other musicians <br/>
-                                  are in your session
-                                </div>
-                            </div>
-                            <br clear="all" />
-                            <div class="recording" id="recording-start-stop">
-                                <a>
-                                    <%= image_tag "content/recordbutton-off.png", {:width => 20, :height => 20, :align => "absmiddle"} %>&nbsp;&nbsp;<span id="recording-status">Make a Recording</span>
-                                </a>
-                            </div>
-                        </div>
-                    </div>
-
-                    <!-- recordings -->
-                    <div class="session-recordings">
-                        <h2>other audio</h2>
-                        <div class="session-recording-name-wrapper">
-                            <div class="session-recording-name left">(No recording loaded)</div>
-                            <div class="session-add right">
-                                <a id='close-playback-recording' href="#"><%= image_tag "content/icon_close.png", {:width => 18, :height => 20, :align => "texttop"} %>&nbsp;&nbsp;Close</a>
-                            </div>
-                        </div>
-                        <div class="session-tracks-scroller">
-                            <div id="session-recordedtracks-container">
-                                <div class="when-empty recordings">
-                                  <span class="open-media-file-header"><%= image_tag "content/icon_folder.png", {width:22, height:20} %> Open:</span>
-                                  <ul class="open-media-file-options">
-                                    <li><a href="#" id="open-a-recording">Recording</a></li>
-                                    <% if Rails.application.config.jam_tracks_available %>
-                                    <li><a href="#" id="open-a-jamtrack">JamTrack</a></li>
-                                    <% end %>
-                                    <!--<li>Audio File</li>-->
-                                  </ul>
-                                </div>
-                            </div>
-                            <br clear="all" />
-
-                          <%= render "play_controls" %>
-
-                        </div>
-
-                        <!-- recording name and close button -->
-                        <!--
-                        <div class="session-recording-name-wrapper">
-                            <div class="session-recording-name left">(No recording loaded)</div>
-                            <div class="session-add right">
-                                <a>
-                                    <%= image_tag "content/icon_close.png", {:width => 18, :height => 20, :align => "texttop"} %>&nbsp;&nbsp;Close
-                                </a>
-                            </div>
-                        </div>
-                        -->
-                    </div>
-
-                </div>
-            </div>
-        </div>
-    </div>
-</div>
-
-<!-- dialogs needed for Session screen (ORDER MATTERS) -->
-<%= render "configureTrack" %>
-<%= render "addTrack" %>
-<%= render "addNewGear" %>
-<%= render "error" %>
-<%= render "sessionSettings" %>
-
-<!-- Track Template -->
-<script type="text/template" id="template-session-track">
-<div track-id="{trackId}" class="session-track track" client-id="{clientId}">
-    <div class="track-vu-left" mixer-id="{vuMixerId}_vul"></div>
-    <div class="track-vu-right" mixer-id="{vuMixerId}_vur"></div>
-    <div class="track-label">{name}</div>
-    <div id="div-track-close" track-id="{trackId}" class="track-close op30">
-        <%= image_tag "content/icon_closetrack.png", {:width => 12, :height => 12} %>
-    </div>
-    <div class="{avatarClass}">
-        <img src="{avatar}"/>
-    </div>
-    <div class="track-instrument {preMasteredClass}">
-        <img src="{instrumentIcon}" width="45" height="45"/>
-    </div>
-    <div class="track-gain" mixer-id="{mixerId}"></div>
-    <!--
-        <div class="track-gain-wrapper" 
-            control="fader" orientation="vertical">
-            <div class="track-gain-slider" style="bottom:{gainPercent}%;" control="fader-handle">
-                <%= image_tag "content/slider_gain_vertical.png", {:width => 28, :height => 11} %>
-            </div>
-        </div>
-    </div>
-    -->
-    <div class="track-icon-mute {muteClass}" control="mute" mixer-id="{muteMixerId}">
-    </div>
-    <!-- TODO - connection class from curly param -->
-    <div mixer-id="{mixerId}_connection" class="track-connection grey">CONNECTION</div>
-    <div class="disabled-track-overlay"></div>
-</div>
-</script>
-
-<script type="text/template" id="template-option">
-    <option value="{value}" title="{label}" {selected}>{label}</option>
-</script>
-
-<!-- Genre option template -->
-<script type="text/template" id="template-genre-option">
-    <option value="{value}">{label}</option>
-</script>
-

web/app/views/clients/_session.html.slim

@@ -0,0 +1,145 @@
+#session-screen.screen.secondary[layout="screen" layout-id="session" layout-arg="id"]
+  .content-head
+    .content-icon
+      = image_tag "shared/icon_session.png", {:height => 19, :width => 19}
+    h1
+      | session
+  .content-body
+    #session-controls
+      a#session-resync.button-grey.resync.left
+        = image_tag "content/icon_resync.png", {:align => "texttop", :height => 14, :width => 12}
+        |  RESYNC 
+      a#session-settings-button.button-grey.left[layout-link="session-settings"]
+        = image_tag "content/icon_settings_sm.png", {:align => "texttop", :height => 12, :width => 12}
+        |  SETTINGS 
+      a.button-grey.left[layout-link="share-dialog"]
+        = image_tag "content/icon_share.png", {:align => "texttop", :height => 12, :width => 12}
+        |  SHARE 
+      .block
+        .label
+          | VOLUME:
+        #volume.fader.lohi[mixer-id=""]
+      .block.monitor-mode-holder
+        .label
+          | MIX:
+        select.monitor-mode.easydropdown
+          option.label[value="personal"]
+            | Personal
+          option[value="master"]
+            | Master
+      a#session-leave.button-grey.right.leave[href="/client#/home"]
+        | X  LEAVE
+    #tracks
+      .content-scroller
+        .content-wrapper
+          .session-mytracks
+            h2
+              | my tracks
+            #track-settings.session-add[style="display:block;" layout-link="configure-tracks"]
+              = image_tag "content/icon_settings_lg.png", {:width => 18, :height => 18}
+              span
+                | Settings
+            .session-tracks-scroller
+              #session-mytracks-container
+              #voice-chat.voicechat[style="display:none;" mixer-id=""]
+                .voicechat-label
+                  | CHAT
+                .voicechat-gain
+                .voicechat-mute.enabled[control="mute" mixer-id=""]
+          .session-livetracks
+            h2
+              | live tracks
+            .session-add[layout-link="select-invites"]
+              a#session-invite-musicians[href="#"]
+                = image_tag "content/icon_add.png", {:width => 19, :height => 19, :align => "texttop"}
+                |   Invite Musicians 
+            .session-tracks-scroller
+              #session-livetracks-container
+                .when-empty.livetracks
+                  |  No other musicians 
+                  br
+                  |  are in your session 
+              br[clear="all"]
+              #recording-start-stop.recording
+                a
+                  = image_tag "content/recordbutton-off.png", {:width => 20, :height => 20, :align => "absmiddle"}
+                  |   
+                  span#recording-status
+                    | Make a Recording
+          .session-recordings
+            h2
+              | other audio
+            .session-recording-name-wrapper
+              .session-recording-name.left
+                | (No recording loaded)
+              .session-add.right
+                a#close-playback-recording[href="#"]
+                  = image_tag "content/icon_close.png", {:width => 18, :height => 20, :align => "texttop"}
+                  |   Close
+            .session-tracks-scroller
+              #session-recordedtracks-container
+                .when-empty.recordings
+                  span.open-media-file-header
+                    = image_tag "content/icon_folder.png", {width:22, height:20}
+                    |  Open:
+                  ul.open-media-file-options
+                    li
+                      a#open-a-recording[href="#"]
+                        | Recording
+                    - if Rails.application.config.jam_tracks_available
+                      li
+                        a#open-a-jamtrack[href="#"]
+                          | JamTrack
+                    - if Rails.application.config.backing_tracks_available
+                      li
+                        a#open-a-backingtrack[href="#"]
+                          | Audio File
+                .when-empty.use-metronome-header
+                  - if Rails.application.config.metronome_available
+                    = image_tag "content/icon_metronome.png", {width:22, height:20}
+                    a#open-a-metronome[href="#"]
+                      | Use Metronome
+              br[clear="all"]
+              = render "play_controls"
+= render "configureTrack"
+= render "addTrack"
+= render "addNewGear"
+= render "error"
+= render "sessionSettings"
+script#template-session-track[type="text/template"]  
+  .session-track.track client-id="{clientId}" track-id="{trackId}"
+    .track-vu-left.mixer-id="{vuMixerId}_vul" 
+    .track-vu-right.mixer-id="{vuMixerId}_vur" 
+    .track-label[title="{name}"]
+      span.name-text="{name}"
+    #div-track-close.track-close.op30 track-id="{trackId}" 
+      =image_tag("content/icon_closetrack.png", {width: 12, height: 12})
+    div class="{avatarClass}" 
+      img src="{avatar}" 
+    .track-instrument class="{preMasteredClass}" 
+      img height="45" src="{instrumentIcon}" width="45" 
+    .track-gain mixer-id="{mixerId}" 
+    .track-icon-mute class="{muteClass}" control="mute" mixer-id="{muteMixerId}" 
+    .track-icon-loop.hidden control="loop"
+      input#loop-button type="checkbox" value="loop" Loop
+    .track-connection.grey mixer-id="{mixerId}_connection"  
+      CONNECTION  
+    .disabled-track-overlay
+    .metronome-selects.hidden
+      select.metronome-select.metro-sound title="Metronome Sound"
+        option.label value="Beep"  Bleep
+        option.label value="Click" Click
+        option.label value="Snare"  Drum
+      br
+      select.metronome-select.metro-tempo title="Metronome Tempo"
+        - metronome_tempos.each do |t|
+          option.label value=t
+            =t
+
+script#template-option type="text/template" 
+  option value="{value}" title="{label}" selected="{selected}"
+    ="{label}"
+
+script#template-genre-option type="text/template" 
+  option value="{value}"
+    ="{label}"            

web/app/views/clients/_sync_viewer_templates.html.slim

@@ -59,6 +59,23 @@ script type="text/template" id='template-sync-viewer-recorded-track'
       a.retry href='#'
         = image_tag('content/icon_resync.png', width:12, height: 14)
 
+script type="text/template" id='template-sync-viewer-recorded-backing-track'
+  .recorded-backing-track.sync data-id="{{data.id}}" data-recording-id="{{data.recording_id}}" data-client-id="{{data.client_id}}" data-client-track-id="{{data.client_track_id}}" data-track-id="{{data.backing_track_id}}" data-fully-uploaded="{{data.fully_uploaded}}"
+    .type
+      span.text BACKING
+      a.avatar-tiny href="#" user-id="{{data.user.id}}" hoveraction="musician"
+        img src="{{JK.resolveAvatarUrl(data.user.photo_url)}}"
+    .client-state.bar
+      .progress
+      span.msg
+      a.retry href='#'
+        = image_tag('content/icon_resync.png', width:12, height: 14)
+    .upload-state.bar
+      .progress
+      span.msg
+      a.retry href='#'
+        = image_tag('content/icon_resync.png', width:12, height: 14)
+
 
 script type="text/template" id='template-sync-viewer-stream-mix'
   .stream-mix.sync data-id="{{data.id}}" data-recording-id="{{data.recording_id}}"
@@ -128,6 +145,33 @@ script type="text/template" id="template-sync-viewer-hover-recorded-track"
       | {{data.summary}}
     | {% } %}
 
+script type="text/template" id="template-sync-viewer-hover-recorded-backing-track"
+  .help-hover-recorded-backing-tracks
+
+    .client-box
+      .client-state-info
+        span.special-text is the file on your system?
+      .client-state class="{{data.clientStateClass}}"
+        span.msg
+          | {{data.clientStateMsg}}
+      .client-state-definition.sync-definition
+        | {{data.clientStateDefinition}}
+    .upload-box
+      .upload-state-info
+        span.special-text is it uploaded?
+      .upload-state class="{{data.uploadStateClass}}"
+        span.msg
+          | {{data.uploadStateMsg}}
+      .upload-state-definition.sync-definition
+        | {{data.uploadStateDefinition}}
+    br clear="both"
+
+    | {% if(data.summary) { %}
+    .summary
+      .title what's next?
+      | {{data.summary}}
+    | {% } %}
+
 script type="text/template" id="template-sync-viewer-hover-stream-mix"
   .help-hover-stream-mix
 
@@ -189,7 +233,7 @@ script type="text/template" id="template-sync-viewer-generic-command"
         | {{data.displayType}}
 
 script type="text/template" id="template-sync-viewer-recorded-track-command"
-  .recorded-track.sync
+  .recorded-track.track-item.sync
     .type
       .progress
       span.text
@@ -198,6 +242,15 @@ script type="text/template" id="template-sync-viewer-recorded-track-command"
         img src="{{JK.resolveAvatarUrl(data.user.photo_url)}}"
       img.instrument-icon data-instrument-id="{{data.instrument_id}}" hoveraction="instrument" src="{{JK.getInstrumentIconMap24()[data.instrument_id].asset}}"
 
+script type="text/template" id="template-sync-viewer-recorded-backing-track-command"
+  .recorded-backing-track.track-item.sync
+    .type
+      .progress
+      span.text
+        | {{data.action}} BACKING TRACK
+      a.avatar-tiny href="#" user-id="{{data.user.id}}" hoveraction="musician"
+        img src="{{JK.resolveAvatarUrl(data.user.photo_url)}}"
+
 script type="text/template" id="template-sync-viewer-log-item"
   .log class="success-{{data.success}}"
     .command

web/app/views/clients/index.html.erb

@@ -155,6 +155,9 @@
             var openJamTrackDialog = new JK.OpenJamTrackDialog(JK.app);
             openJamTrackDialog.initialize();
 
+            var openBackingTrackDialog = new JK.OpenBackingTrackDialog(JK.app);
+            openBackingTrackDialog.initialize();
+
             var configureTracksDialog = new JK.ConfigureTracksDialog(JK.app);
             configureTracksDialog.initialize();
 

web/app/views/dialogs/_dialogs.html.haml

@@ -33,3 +33,4 @@
 = render 'dialogs/allSyncsDialog'
 = render 'dialogs/adjustGearSpeedDialog'
 = render 'dialogs/openJamTrackDialog'
+= render 'dialogs/openBackingTrackDialog'

web/app/views/dialogs/_openBackingTrackDialog.html.slim

@@ -0,0 +1,44 @@
+.dialog.openBackingTrackDialog-overlay.ftue-overlay.tall#open-backing-track-dialog layout="dialog" layout-id="open-backing-track-dialog"
+
+  .content-head
+    = image_tag "content/icon_add.png", {:width => 19, :height => 19, :class => 'content-icon' }
+    h1
+      | open an audio file
+
+  .dialog-inner
+
+    .recording-wrapper
+      table.open-backing-tracks cellspacing="0" cellpadding="0" border="0"
+        thead
+          tr
+            th align="left"
+              | NAME
+            th align="left"
+              | SIZE
+            th align="left"
+              | TYPE
+        tbody
+    br
+
+    / .left.paginator-holder
+
+    .help-links
+      a.display-backingtracks-folder href='#'
+        | Display audio file folder
+      a.what-are-backingtracks href='#'
+        | What are Backing Tracks?      
+    .right
+      a href="#" class="button-grey" layout-action="close"
+        | CANCEL
+    br clear="all"
+
+  script#template-backing-track-row type="text/template"
+    tr data-recording-id="{{data.backingTrackId}}" data-local-state="{{data.backingTrackState}}"
+      td
+        | {{data.name}}
+      td
+        | {{data.length}}      
+      td
+        | {{data.type}}
+
+

web/config/application.rb

@@ -39,7 +39,7 @@ if defined?(Bundler)
 
     # Activate observers that should always be running.
     # config.active_record.observers = :cacher, :garbage_collector, :forum_observer
-    config.active_record.observers = "JamRuby::InvitedUserObserver", "JamRuby::UserObserver", "JamRuby::FeedbackObserver", "JamRuby::RecordedTrackObserver", "JamRuby::QuickMixObserver"
+    config.active_record.observers = "JamRuby::InvitedUserObserver", "JamRuby::UserObserver", "JamRuby::FeedbackObserver", "JamRuby::RecordedTrackObserver", "JamRuby::QuickMixObserver", "JamRuby::RecordedBackingTrackObserver"
 
     # Set Time.zone default to the specified zone and make Active Record auto-convert to this zone.
     # Run "rake -D time" for a list of tasks for finding time zone names. Default is UTC.
@@ -312,5 +312,7 @@ if defined?(Bundler)
 
     config.show_jamblaster_notice = true
     config.show_jamblaster_kickstarter_link = true
+    config.metronome_available = true
+    config.backing_tracks_available = true
   end
 end

web/config/routes.rb

@@ -184,6 +184,10 @@ SampleApp::Application.routes.draw do
     match '/sessions/:id/details/comments' => 'api_music_sessions#add_session_info_comment', :via => :post
     match '/sessions/:id/jam_tracks/:jam_track_id/open' => 'api_music_sessions#jam_track_open', :via => :post
     match '/sessions/:id/jam_tracks/close' => 'api_music_sessions#jam_track_close', :via => :post
+    match '/sessions/:id/backing_tracks/open' => 'api_music_sessions#backing_track_open', :via => :post
+    match '/sessions/:id/backing_tracks/close' => 'api_music_sessions#backing_track_close', :via => :post
+    match '/sessions/:id/metronome/open' => 'api_music_sessions#metronome_open', :via => :post
+    match '/sessions/:id/metronome/close' => 'api_music_sessions#metronome_close', :via => :post
 
     # music session tracks
     match '/sessions/:id/tracks' => 'api_music_sessions#track_create', :via => :post
@@ -197,6 +201,9 @@ SampleApp::Application.routes.draw do
     match '/music_notations' => 'api_music_notations#create', :via => :post
     match '/music_notations/:id' => 'api_music_notations#download', :via => :get, :as => :download_music_notation
 
+    # Backing track_show
+    match '/backing_tracks' => 'api_backing_tracks#index', :via => :get, :as => 'api_backing_tracks_list'
+
     # Jamtracks
     match '/jamtracks' => 'api_jam_tracks#index', :via => :get, :as => 'api_jam_tracks_list'
     match '/jamtracks/purchased' => 'api_jam_tracks#purchased', :via => :get, :as => 'api_jam_tracks_purchased'
@@ -453,13 +460,22 @@ SampleApp::Application.routes.draw do
     match '/recordings/:id/tracks/:track_id/upload_sign' => 'api_recordings#upload_sign', :via => :get
     match '/recordings/:id/tracks/:track_id/upload_part_complete' => 'api_recordings#upload_part_complete', :via => :post
     match '/recordings/:id/tracks/:track_id/upload_complete' => 'api_recordings#upload_complete', :via => :post
-    match '/recordings/:id/stream_mix/upload_next_part' => 'api_recordings#upload_next_part_stream_mix', :via => :get
 
     # Recordings - stream_mix
     match '/recordings/:id/stream_mix/upload_sign' => 'api_recordings#upload_sign_stream_mix', :via => :get
     match '/recordings/:id/stream_mix/upload_part_complete' => 'api_recordings#upload_part_complete_stream_mix', :via => :post
     match '/recordings/:id/stream_mix/upload_complete' => 'api_recordings#upload_complete_stream_mix', :via => :post
-    
+    match '/recordings/:id/stream_mix/upload_next_part' => 'api_recordings#upload_next_part_stream_mix', :via => :get
+
+    # Recordings - backing tracks
+    match '/recordings/:id/backing_tracks/:track_id' => 'api_recordings#show_recorded_backing_track', :via => :get, :as => 'api_recordings_show_recorded_backing_track'
+    match '/recordings/:id/backing_tracks/:track_id/download' => 'api_recordings#backing_track_download', :via => :get, :as => 'api_recordings_download'
+    match '/recordings/:id/backing_tracks/:track_id/upload_next_part' => 'api_recordings#backing_track_upload_next_part', :via => :get
+    match '/recordings/:id/backing_tracks/:track_id/upload_sign' => 'api_recordings#backing_track_upload_sign', :via => :get
+    match '/recordings/:id/backing_tracks/:track_id/upload_part_complete' => 'api_recordings#backing_track_upload_part_complete', :via => :post
+    match '/recordings/:id/backing_tracks/:track_id/upload_complete' => 'api_recordings#backing_track_upload_complete', :via => :post
+    match '/recordings/:id/backing_tracks/:track_id/silent' => 'api_backing_tracks#backing_track_silent', :via => :post
+
     # Recordings - recorded_videos
     match '/recordings/:id/tracks/:video_id/upload_sign' => 'api_recordings#video_upload_sign', :via => :get
     match '/recordings/:id/videos/:video_id/upload_start' => 'api_recordings#video_upload_start', :via => :post

web/lib/music_session_manager.rb

@@ -140,10 +140,10 @@ class MusicSessionManager < BaseManager
     Notification.send_session_depart(active_music_session, connection.client_id, user, recordingId)
   end
 
-  def sync_tracks(active_music_session, client_id, new_tracks)
+  def sync_tracks(active_music_session, client_id, new_tracks, backing_tracks)
     tracks = nil
     active_music_session.with_lock do # VRFS-1297
-      tracks = Track.sync(client_id, new_tracks)
+      tracks = Track.sync(client_id, new_tracks, backing_tracks)
       active_music_session.tick_track_changes
     end
     Notification.send_tracks_changed(active_music_session)

web/spec/controllers/api_music_sessions_controller_spec.rb

@@ -223,4 +223,87 @@ describe ApiMusicSessionsController do
       json[:jam_track][:id].should == jam_track.id
     end
   end
+
+  describe "open_backing_track" do
+
+    let(:ams) { FactoryGirl.create(:active_music_session, creator: user) }
+    let(:backing_track) { "foo.mp3"}
+
+    it "does not allow someone to open a track unless they are in the session" do
+      post :backing_track_open, {:format => 'json', id: ams.id, backing_track_path: backing_track}
+      response.status.should == 403
+    end
+
+    it "does not allow someone to open a track unless they own the backing track" do
+      pending "connection with client to determine ownership"
+      conn.join_the_session(ams.music_session, true, tracks, user, 10)
+
+      post :backing_track_open, {:format => 'json', id: ams.id, backing_track_path: backing_track}
+      response.status.should == 403
+    end
+
+    it "allows someone who owns the backing track to open it" do
+      # put the connection of the user into the session, so th
+      conn.join_the_session(ams.music_session, true, tracks, user, 10)
+      
+      post :backing_track_open, {:format => 'json', id: ams.id, backing_track_path: backing_track}
+      response.status.should == 200
+    end
+
+    it "does not allow someone to close a track unless they are in the session" do
+      post :backing_track_close, {:format => 'json', id: ams.id}
+      response.status.should == 403
+    end
+
+    it "allows the backing track to be closed" do
+      # put the connection of the user into the session, so th
+      conn.join_the_session(ams.music_session, true, tracks, user, 10)
+      
+      post :backing_track_open, {:format => 'json', id: ams.id, backing_track_path: backing_track}
+      response.status.should == 200
+
+      post :backing_track_close, {:format => 'json', id: ams.id}
+      response.status.should == 200
+    end
+  end
+
+  describe "open_metronome" do
+
+    let(:ams) { FactoryGirl.create(:active_music_session, creator: user) }
+    let(:metronome) { "foo.mp3"}
+
+    it "does not allow someone to open a track unless they are in the session" do
+      post :metronome_open, {:format => 'json', id: ams.id, metronome_path: metronome}
+      response.status.should == 403
+    end
+
+    it "can open it" do
+      conn.join_the_session(ams.music_session, true, tracks, user, 10)
+      
+      post :metronome_open, {:format => 'json', id: ams.id, metronome_path: metronome}
+      response.status.should == 200
+    end
+
+    it "does not allow someone to close a metronome" do
+      post :metronome_close, {:format => 'json', id: ams.id}
+      response.status.should == 403
+    end
+
+    it "does allow someone who joied to close a metronome" do
+      conn.join_the_session(ams.music_session, true, tracks, user, 10)
+      post :metronome_close, {:format => 'json', id: ams.id}
+      response.status.should == 200
+    end
+
+    it "allows the metronome to be closed" do
+      # put the connection of the user into the session, so th
+      conn.join_the_session(ams.music_session, true, tracks, user, 10)
+      
+      post :metronome_open, {:format => 'json', id: ams.id, metronome_path: metronome}
+      response.status.should == 200
+
+      post :metronome_close, {:format => 'json', id: ams.id}
+      response.status.should == 200
+    end
+  end
 end

web/spec/controllers/api_recordings_controller_spec.rb

@@ -10,6 +10,7 @@ describe ApiRecordingsController do
     @music_session = FactoryGirl.create(:active_music_session, :creator => @user, :musician_access => true)
     @connection = FactoryGirl.create(:connection, :user => @user, :music_session => @music_session)
     @track = FactoryGirl.create(:track, :connection => @connection, :instrument => @instrument)
+    @backing_track = FactoryGirl.create(:backing_track, :connection => @connection)
     controller.current_user = @user
   end
 
@@ -100,7 +101,65 @@ describe ApiRecordingsController do
     end
   end
 
-  describe "download" do
+  describe "download track" do
+    let(:mix) { FactoryGirl.create(:mix) }
+
+    it "should only allow a user to download a track if they have claimed the recording" do
+      post :start, { :format => 'json', :music_session_id => @music_session.id }
+      response_body = JSON.parse(response.body)
+      recording = Recording.find(response_body['id'])
+      post :stop, { :format => 'json', :id => recording.id }
+      response.should be_success
+    end
+
+
+    it "is possible" do
+      mix.touch
+      recorded_track = mix.recording.recorded_tracks[0]
+      controller.current_user = mix.recording.owner
+      get :download, {id: recorded_track.recording.id, track_id: recorded_track.client_track_id}
+      response.status.should == 302
+
+      recorded_track.reload
+      recorded_track.download_count.should == 1
+
+      get :download, {id: recorded_track.recording.id, track_id: recorded_track.client_track_id}
+      response.status.should == 302
+
+      recorded_track.reload
+      recorded_track.download_count.should == 2
+    end
+
+
+    it "prevents download after limit is reached" do
+      mix.touch
+      recorded_track = mix.recording.recorded_tracks[0]
+      recorded_track.download_count = APP_CONFIG.max_audio_downloads
+      recorded_track.save!
+      controller.current_user = recorded_track.user
+      get :download, {format:'json', id: recorded_track.recording.id, track_id: recorded_track.client_track_id}
+      response.status.should == 404
+      JSON.parse(response.body, symbolize_names: true)[:message].should == "download limit surpassed"
+    end
+
+
+    it "lets admins surpass limit" do
+      mix.touch
+      recorded_track = mix.recording.recorded_tracks[0]
+      recorded_track.download_count = APP_CONFIG.max_audio_downloads
+      recorded_track.save!
+      recorded_track.user.admin = true
+      recorded_track.user.save!
+
+      controller.current_user = recorded_track.user
+      get :download, {format:'json', id: recorded_track.recording.id, track_id: recorded_track.client_track_id}
+      response.status.should == 302
+      recorded_track.reload
+      recorded_track.download_count.should == 101
+    end
+  end
+
+  describe "download backing track" do
     let(:mix) { FactoryGirl.create(:mix) }
 
     it "should only allow a user to download a track if they have claimed the recording" do

web/spec/factories.rb

@@ -274,6 +274,11 @@ FactoryGirl.define do
     sequence(:client_resource_id) { |n| "resource_id#{n}"}
   end
 
+  factory :backing_track, :class => JamRuby::BackingTrack do
+    sequence(:client_track_id) { |n| "client_track_id#{n}"}
+    filename 'foo.mp3'
+  end
+
   factory :video_source, :class => JamRuby::VideoSource do
     #client_video_source_id "test_source_id"    
     sequence(:client_video_source_id) { |n| "client_video_source_id#{n}"}
@@ -303,6 +308,19 @@ FactoryGirl.define do
     association :recording,     factory: :recording
   end
 
+  factory :recorded_backing_track, :class => JamRuby::RecordedBackingTrack do
+    sequence(:client_id) { |n| "client_id-#{n}"}
+    sequence(:backing_track_id) { |n| "track_id-#{n}"}
+    sequence(:client_track_id) { |n| "client_track_id-#{n}"}
+    sequence(:filename) { |n| "filename-{#n}"}
+    sequence(:url) { |n| "/recordings/blah/#{n}"}
+    md5 'abc'
+    length 1
+    fully_uploaded true
+    association :user,          factory: :user
+    association :recording,     factory: :recording
+  end
+
   factory :recorded_video, :class => JamRuby::RecordedVideo do 
     sequence(:recording_id) { |n| "recording_id-#{n}"}
     sequence(:client_video_source_id) { |n| "client_video_source_id-#{n}"}

web/spec/features/find_sessions_spec.rb

@@ -9,6 +9,10 @@ describe "Find Session", :js => true, :type => :feature, :capybara_feature => tr
   let(:dallas) { dallas_geoip }
   let(:user) { FactoryGirl.create(:user, last_jam_locidispid: austin_geoip[:locidispid], last_jam_addr: austin_ip) }
   let(:finder) { FactoryGirl.create(:user, last_jam_locidispid: dallas_geoip[:locidispid], last_jam_addr: dallas_ip) }
+  
+  before(:all) do
+    Capybara.default_wait_time = 20
+  end
 
 
   before(:each) do
@@ -82,7 +86,7 @@ describe "Find Session", :js => true, :type => :feature, :capybara_feature => tr
 
           # this should cause it to move to the scheduled session view; we'll check all the values again
           ActiveMusicSession.delete_all
-
+          sleep(3)
           verify_find_session_score(nil,   '#sessions-scheduled', session1_creator, session1_creator)
 
           fast_signout

web/spec/features/in_session_spec.rb

@@ -59,7 +59,8 @@ describe "In a Session", :js => true, :type => :feature, :capybara_feature => tr
     end
 
     leave_music_session_sleep_delay
-    in_client(finder) { expect(page).to_not have_selector('div.track-label',  text: user.name) }
+    in_client(finder) { expect(page).to_not have_selector("div.track-label[title='#{user.name}']") }
+
   end
 
   many = 4
@@ -110,6 +111,27 @@ describe "In a Session", :js => true, :type => :feature, :capybara_feature => tr
     end
   end
 
+  specify "metronome" do
+    pending "working through issue with fake media tracks"
+    user = FactoryGirl.create(:user)
+    invitee = FactoryGirl.create(:user)
+    FactoryGirl.create(:friendship, :user => user, :friend => invitee)
+    in_client(user) do
+      create_session
+      
+      # Call it 10 times.  The fake jam client will randomly ntp_stable:false 50% of the time
+      10.times do 
+        find('#open-a-metronome').trigger(:click)
+      end
+      sleep(2)
+      
+      # we should have received an error one of the times, but it should open eventually:
+      find('#notification').should have_text("Couldn't open metronome")
+      expect(page).to have_selector('.track-label[title="Metronome"]')
+      #save_screenshot("metro.png")      
+    end
+  end      
+
   specify "invitee receives notification when creator invites musician" do
     pending "blocked on testing this via front-end - fakeJamClient doesn't support invite UX"
     user = FactoryGirl.create(:user)

web/spec/spec_helper.rb

@@ -192,6 +192,12 @@ bputs "before register capybara"
     end
 
     config.before(:all) do
+      # to reduce frequency of timeout on initial test
+      # https://github.com/teampoltergeist/poltergeist/issues/294#issuecomment-72746472
+      if self.respond_to? :visit
+        visit '/assets/application.css'
+        visit '/assets/application.js'
+      end
     end
 
     config.before(:each) do

web/spec/support/utilities.rb

@@ -637,7 +637,7 @@ def assert_all_tracks_seen(users=[])
   users.each do |user|
     in_client(user) do
       users.reject {|u| u==user}.each do |other|
-        find('div.track-label',  text: other.name)
+        find("div.track-label[title='#{other.name}']")
         #puts user.name + " is able to see " + other.name + "\'s track"
       end
     end

websocket-gateway/lib/jam_websockets/router.rb

@@ -709,6 +709,10 @@ module JamWebsockets
 
               unless music_session_upon_reentry.nil? || music_session_upon_reentry.destroyed?
 
+                if music_session_upon_reentry.backing_track_initiator == user
+                  music_session_upon_reentry.close_backing_track
+                end
+
                 # if a jamtrack is open and this user is no longer in the session, close it
                 if music_session_upon_reentry.jam_track_initiator == user
                   music_session_upon_reentry.close_jam_track