diff --git a/pb/src/client_container.proto b/pb/src/client_container.proto
index 8e47b148b..ffa1478b7 100644
--- a/pb/src/client_container.proto
+++ b/pb/src/client_container.proto
@@ -46,7 +46,6 @@ message ClientMessage {
         SCHEDULED_SESSION_REMINDER              = 181;
         SCHEDULED_SESSION_COMMENT               = 182;
 
-
         // recording notifications
         MUSICIAN_RECORDING_SAVED            = 200;
         BAND_RECORDING_SAVED                = 205;
diff --git a/ruby/lib/jam_ruby.rb b/ruby/lib/jam_ruby.rb
index 2ea2b5a2b..acbcdb4ff 100755
--- a/ruby/lib/jam_ruby.rb
+++ b/ruby/lib/jam_ruby.rb
@@ -66,6 +66,8 @@ require "jam_ruby/models/max_mind_isp"
 require "jam_ruby/models/band_genre"
 require "jam_ruby/models/genre"
 require "jam_ruby/models/user"
+require "jam_ruby/models/rsvp_request"
+require "jam_ruby/models/rsvp_slot"
 require "jam_ruby/models/user_observer"
 require "jam_ruby/models/user_authorization"
 require "jam_ruby/models/join_request"
diff --git a/ruby/lib/jam_ruby/message_factory.rb b/ruby/lib/jam_ruby/message_factory.rb
index 66dd94f5e..784d5965a 100644
--- a/ruby/lib/jam_ruby/message_factory.rb
+++ b/ruby/lib/jam_ruby/message_factory.rb
@@ -452,14 +452,14 @@ module JamRuby
       )
     end
 
-            # SCHEDULED_SESSION_RSVP                  = 175;
-        # SCHEDULED_SESSION_RSVP_APPROVED         = 176;
-        # SCHEDULED_SESSION_RSVP_CANCELLED        = 177;
-        # SCHEDULED_SESSION_RSVP_CANCELLED_ORG    = 178;
-        # SCHEDULED_SESSION_CANCELLED             = 179;
-        # SCHEDULED_SESSION_RESCHEDULED           = 180;
-        # SCHEDULED_SESSION_REMINDER              = 181;
-        # SCHEDULED_SESSION_COMMENT               = 182;
+    # SCHEDULED_SESSION_RSVP                  = 175;
+    # SCHEDULED_SESSION_RSVP_APPROVED         = 176;
+    # SCHEDULED_SESSION_RSVP_CANCELLED        = 177;
+    # SCHEDULED_SESSION_RSVP_CANCELLED_ORG    = 178;
+    # SCHEDULED_SESSION_CANCELLED             = 179;
+    # SCHEDULED_SESSION_RESCHEDULED           = 180;
+    # SCHEDULED_SESSION_REMINDER              = 181;
+    # SCHEDULED_SESSION_COMMENT               = 182;
 
     def scheduled_session_rsvp(receiver_id, session_id, photo_url, msg, slots, instruments, session_name, session_date, notification_id, created_at)
       scheduled_session_rsvp = Jampb::ScheduledSessionRsvp.new(
@@ -479,7 +479,6 @@ module JamRuby
       )
     end
 
-
     def band_session_join(receiver_id, session_id, photo_url, fan_access, musician_access, approval_required, msg, notification_id, created_at)
       band_session_join = Jampb::BandSessionJoin.new(
           :session_id => session_id,
diff --git a/ruby/lib/jam_ruby/models/rsvp_request.rb b/ruby/lib/jam_ruby/models/rsvp_request.rb
new file mode 100644
index 000000000..28ca90401
--- /dev/null
+++ b/ruby/lib/jam_ruby/models/rsvp_request.rb
@@ -0,0 +1,17 @@
+module JamRuby
+  class RsvpRequest < ActiveRecord::Base
+
+    belongs_to :user, :class_name => "JamRuby::User"
+    belongs_to :rsvp_slot, :class_name => "JamRuby::RsvpSlot"
+
+    validates :message, length: {maximum: 1000}, no_profanity: true
+    validates :chosen, :inclusion => {:in => [nil, true, false]}
+    validates :canceled, :inclusion => {:in => [nil, true, false]}
+    validates :rsvp_slot, presence: true
+
+
+    # XXX we need to validate that only one RsvpRequest.chosen = true for a given RsvpSlot
+    # in other words, you can have many requests to a slot, but only 0 or 1 rsvp_request.chosen = true)
+  end
+
+end
diff --git a/ruby/lib/jam_ruby/models/rsvp_slot.rb b/ruby/lib/jam_ruby/models/rsvp_slot.rb
new file mode 100644
index 000000000..7559fee7f
--- /dev/null
+++ b/ruby/lib/jam_ruby/models/rsvp_slot.rb
@@ -0,0 +1,10 @@
+module JamRuby
+  class RsvpSlot < ActiveRecord::Base
+
+    belongs_to :instrument, :class_name => "JamRuby::Instrument"
+    belongs_to :music_session
+    has_many :rsvp_requests, :class_name => "JamRuby::RsvpRequest"
+
+    # TODO: validates :proficiency_level
+  end
+end
diff --git a/ruby/spec/factories.rb b/ruby/spec/factories.rb
index e914a2d66..20b37fb77 100644
--- a/ruby/spec/factories.rb
+++ b/ruby/spec/factories.rb
@@ -458,4 +458,18 @@ FactoryGirl.define do
     creator JamRuby::Diagnostic::CLIENT
     data Faker::Lorem.sentence
   end
+
+  factory :rsvp_slot, class: JamRuby::RsvpSlot do
+    association :instrument, factory: :instrument
+    association :music_session, factory: :music_session
+    proficiency_level 'beginner'
+  end
+
+  factory :rsvp_request, class: JamRuby::RsvpRequest do
+    association :user, factory: :user
+    association :rsvp_slot, factory: :rsvp_slot
+    sequence(:message)           { |n| "I want to join!#{n}" }
+    chosen false
+    canceled false
+  end
 end
diff --git a/ruby/spec/jam_ruby/models/rsvp_request_spec.rb b/ruby/spec/jam_ruby/models/rsvp_request_spec.rb
new file mode 100644
index 000000000..02e137a6b
--- /dev/null
+++ b/ruby/spec/jam_ruby/models/rsvp_request_spec.rb
@@ -0,0 +1,8 @@
+require 'spec_helper'
+
+describe RsvpRequest do
+
+  it "success" do
+    FactoryGirl.create(:rsvp_request)
+  end
+end
\ No newline at end of file
diff --git a/ruby/spec/jam_ruby/models/rsvp_slot_spec.rb b/ruby/spec/jam_ruby/models/rsvp_slot_spec.rb
new file mode 100644
index 000000000..0dfd52eaa
--- /dev/null
+++ b/ruby/spec/jam_ruby/models/rsvp_slot_spec.rb
@@ -0,0 +1,8 @@
+require 'spec_helper'
+
+describe RsvpSlot do
+
+  it "success" do
+    FactoryGirl.create(:rsvp_slot)
+  end
+end
\ No newline at end of file
diff --git a/web/app/assets/javascripts/AAB_message_factory.js b/web/app/assets/javascripts/AAB_message_factory.js
index db1c72816..4108ea118 100644
--- a/web/app/assets/javascripts/AAB_message_factory.js
+++ b/web/app/assets/javascripts/AAB_message_factory.js
@@ -33,8 +33,9 @@
         JOIN_REQUEST_REJECTED     : "JOIN_REQUEST_REJECTED",
         SESSION_JOIN              : "SESSION_JOIN",
         SESSION_DEPART            : "SESSION_DEPART",
-        MUSICIAN_SESSION_JOIN     : "MUSICIAN_SESSION_JOIN",
         TRACKS_CHANGED            : "TRACKS_CHANGED",
+        MUSICIAN_SESSION_JOIN     : "MUSICIAN_SESSION_JOIN",
+        BAND_SESSION_JOIN         : "BAND_SESSION_JOIN",
         SCHEDULED_SESSION_INVITATION            : "SCHEDULED_SESSION_INVITATION",
         SCHEDULED_SESSION_RSVP                  : "SCHEDULED_SESSION_RSVP",
         SCHEDULED_SESSION_RSVP_APPROVED         : "SCHEDULED_SESSION_RSVP_APPROVED",
@@ -56,7 +57,6 @@
         // band notifications
         BAND_INVITATION           : "BAND_INVITATION",
         BAND_INVITATION_ACCEPTED  : "BAND_INVITATION_ACCEPTED",
-        BAND_SESSION_JOIN         : "BAND_SESSION_JOIN",
 
         // text message
         TEXT_MESSAGE              : "TEXT_MESSAGE",
diff --git a/web/app/assets/javascripts/layout.js b/web/app/assets/javascripts/layout.js
index 3272380ce..ebc4990af 100644
--- a/web/app/assets/javascripts/layout.js
+++ b/web/app/assets/javascripts/layout.js
@@ -807,7 +807,6 @@
       }
 
       notifyQueue.push({message: message, descriptor: buttons});
-
       // JW - speeding up the in/out parts of notify. Extending non-moving time.
       $notify.slideDown(250)
         .delay(4000)