diff --git a/db/manifest b/db/manifest
index c75998c34..1100ddac2 100755
--- a/db/manifest
+++ b/db/manifest
@@ -314,4 +314,5 @@ giftcard.sql
 add_description_to_crash_dumps.sql
 acappella.sql
 purchasable_gift_cards.sql
-versionable_jamtracks.sql
\ No newline at end of file
+versionable_jamtracks.sql
+session_controller.sql
\ No newline at end of file
diff --git a/db/up/session_controller.sql b/db/up/session_controller.sql
new file mode 100644
index 000000000..d146481b6
--- /dev/null
+++ b/db/up/session_controller.sql
@@ -0,0 +1 @@
+ALTER TABLE music_sessions ADD COLUMN session_controller_id VARCHAR(64) REFERENCES users(id);
\ No newline at end of file
diff --git a/ruby/lib/jam_ruby/connection_manager.rb b/ruby/lib/jam_ruby/connection_manager.rb
index 352048dc0..748e50eb9 100644
--- a/ruby/lib/jam_ruby/connection_manager.rb
+++ b/ruby/lib/jam_ruby/connection_manager.rb
@@ -28,13 +28,13 @@ module JamRuby
 
     ##### TODO: refactored to notification.rb but left here for backwards compatibility w/ connection_manager_spec.rb
     def gather_friends(connection, user_id)
-        friend_ids = []
-        connection.exec("SELECT f1.friend_id as friend_id FROM friendships f1 WHERE f1.user_id = $1 AND f1.friend_id IN (SELECT f2.user_id FROM friendships f2 WHERE f2.friend_id = $1)", [user_id]) do |friend_results|
-          friend_results.each do |friend_result|
-            friend_ids.push(friend_result['friend_id'])
-          end
+      friend_ids = []
+      connection.exec("SELECT f1.friend_id as friend_id FROM friendships f1 WHERE f1.user_id = $1 AND f1.friend_id IN (SELECT f2.user_id FROM friendships f2 WHERE f2.friend_id = $1)", [user_id]) do |friend_results|
+        friend_results.each do |friend_result|
+          friend_ids.push(friend_result['friend_id'])
         end
-        return friend_ids
+      end
+      return friend_ids
     end
 
     # this simulates music_session destroy callbacks with activerecord
@@ -42,7 +42,7 @@ module JamRuby
       music_session = ActiveMusicSession.find_by_id(music_session_id)
       music_session.before_destroy if music_session
     end
-  
+
     # reclaim the existing connection, if ip_address is not nil then perhaps a new address as well
     def reconnect(conn, channel_id, reconnect_music_session_id, ip_address, connection_stale_time, connection_expire_time, udp_reachable, gateway)
       music_session_id = nil
@@ -65,11 +65,19 @@ module JamRuby
 
         isp = JamIsp.lookup(addr)
         #puts("============= JamIsp.lookup returns #{isp.inspect} for #{addr} =============")
-        if isp.nil? then ispid = 0 else ispid = isp.coid end
+        if isp.nil? then
+          ispid = 0
+        else
+          ispid = isp.coid
+        end
 
         block = GeoIpBlocks.lookup(addr)
         #puts("============= GeoIpBlocks.lookup returns #{block.inspect} for #{addr} =============")
-        if block.nil? then locid = 0 else locid = block.locid end
+        if block.nil? then
+          locid = 0
+        else
+          locid = block.locid
+        end
 
         location = GeoIpLocations.find_by_locid(locid)
         if location.nil? || isp.nil? || block.nil?
@@ -183,11 +191,19 @@ SQL
 
         isp = JamIsp.lookup(addr)
         #puts("============= JamIsp.lookup returns #{isp.inspect} for #{addr} =============")
-        if isp.nil? then ispid = 0 else ispid = isp.coid end
+        if isp.nil? then
+          ispid = 0
+        else
+          ispid = isp.coid
+        end
 
         block = GeoIpBlocks.lookup(addr)
         #puts("============= GeoIpBlocks.lookup returns #{block.inspect} for #{addr} =============")
-        if block.nil? then locid = 0 else locid = block.locid end
+        if block.nil? then
+          locid = 0
+        else
+          locid = block.locid
+        end
 
         location = GeoIpLocations.find_by_locid(locid)
         if location.nil? || isp.nil? || block.nil?
@@ -199,11 +215,11 @@ SQL
         lock_connections(conn)
 
         conn.exec("INSERT INTO connections (user_id, client_id, channel_id, ip_address, client_type, addr, locidispid, aasm_state, stale_time, expire_time, udp_reachable, gateway) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12)",
-                                           [user_id, client_id, channel_id, ip_address, client_type, addr, locidispid, Connection::CONNECT_STATE.to_s, connection_stale_time, connection_expire_time, udp_reachable, gateway]).clear
+                  [user_id, client_id, channel_id, ip_address, client_type, addr, locidispid, Connection::CONNECT_STATE.to_s, connection_stale_time, connection_expire_time, udp_reachable, gateway]).clear
 
         # we just created a new connection-if this is the first time the user has shown up, we need to send out a message to his friends
         conn.exec("SELECT count(user_id) FROM connections WHERE user_id = $1", [user_id]) do |result|
-          count = result.getvalue(0, 0) .to_i
+          count = result.getvalue(0, 0).to_i
           # we're passing all this stuff so that the user record might be updated as well...
           blk.call(conn, count) unless blk.nil?
         end
@@ -291,7 +307,7 @@ SQL
 
         # destroy the music_session if it's empty
         num_participants = nil
-        conn.exec("SELECT count(*) FROM connections WHERE music_session_id = $1", 
+        conn.exec("SELECT count(*) FROM connections WHERE music_session_id = $1",
                   [previous_music_session_id]) do |result|
           num_participants = result.getvalue(0, 0).to_i
         end
@@ -324,11 +340,65 @@ SQL
 
           conn.exec("UPDATE active_music_sessions set jam_track_id = NULL, jam_track_initiator_id = NULL where jam_track_initiator_id = $1 and id = $2",
                     [user_id, previous_music_session_id])
+
+          update_session_controller(previous_music_session_id)
         end
 
       end
     end
 
+    def update_session_controller(music_session_id)
+      active_music_session = ActiveMusicSession.find(music_session_id)
+
+      if active_music_session
+        music_session = active_music_session.music_session
+        if music_session.session_controller_id && !active_music_session.users.exists?(music_session.session_controller)
+          # find next in line, because the current 'session controller' is not part of the session
+          next_in_line(music_session, active_music_session)
+        end
+      end
+    end
+
+    # determine who should be session controller after someone leaves
+    def next_in_line(music_session, active_music_session)
+      session_users = active_music_session.users
+
+      # check friends 1st
+      session_friends = music_session.creator.friends && session_users
+      if session_friends.length > 0
+        music_session.session_controller = session_friends[0]
+        if music_session.save
+          active_music_session.tick_track_changes
+          Notification.send_tracks_changed(active_music_session)
+          return
+        end
+      end
+
+      # check invited 2nd
+      invited = music_session.invited_musicians && session_users
+      if invited.length > 0
+        music_session.session_controller = invited[0]
+        if music_session.save
+          active_music_session.tick_track_changes
+          Notification.send_tracks_changed(active_music_session)
+          return
+        end
+      end
+
+      # go by who joined earliest
+      earliest = active_music_sessions.connections.order(:joined_session_at).first
+
+      if earliest
+        music_session.session_controller = earliest
+        if music_session.save
+          active_music_session.tick_track_changes
+          Notification.send_tracks_changed(active_music_session)
+          return
+        end
+      end
+      music_session.creator
+    end
+
     def join_music_session(user, client_id, music_session, as_musician, tracks, audio_latency, video_sources=nil)
       connection = nil
 
@@ -349,7 +419,10 @@ SQL
 
         if connection.errors.any?
           raise ActiveRecord::Rollback
+        else
+          update_session_controller(music_session.id)
         end
+
       end
 
       connection
@@ -383,6 +456,8 @@ SQL
           if result.cmd_tuples == 1
             @log.debug("disassociated music_session with connection for client_id=#{client_id}, user_id=#{user_id}")
 
+            update_session_controller(music_session.id)
+
             JamRuby::MusicSessionUserHistory.removed_music_session(user_id, music_session_id)
             session_checks(conn, previous_music_session_id, user_id)
             blk.call() unless blk.nil?
diff --git a/ruby/lib/jam_ruby/models/music_session.rb b/ruby/lib/jam_ruby/models/music_session.rb
index 1f56efc08..d2998a72b 100644
--- a/ruby/lib/jam_ruby/models/music_session.rb
+++ b/ruby/lib/jam_ruby/models/music_session.rb
@@ -36,6 +36,8 @@ module JamRuby
 
     belongs_to :active_music_session, :class_name => 'JamRuby::ActiveMusicSession', foreign_key: :music_session_id
 
+    belongs_to :session_controller, :class_name => 'JamRuby::User', :foreign_key => :session_controller_id, :inverse_of => :controlled_sessions
+
     has_many :music_session_user_histories, :class_name => "JamRuby::MusicSessionUserHistory", :foreign_key => "music_session_id", :dependent => :delete_all
     has_many :comments, :class_name => "JamRuby::MusicSessionComment", :foreign_key => "music_session_id"
     has_many :session_info_comments, :class_name => "JamRuby::SessionInfoComment", :foreign_key => "music_session_id"
@@ -116,6 +118,7 @@ module JamRuby
         new_session.open_rsvps = self.open_rsvps
         new_session.is_unstructured_rsvp = self.is_unstructured_rsvp
         new_session.legal_terms = true
+        new_session.session_controller = self.session_controller
 
         # copy rsvp_slots, rsvp_requests, and rsvp_requests_rsvp_slots
         RsvpSlot.find_each(:conditions => "music_session_id = '#{self.id}'") do |slot|
@@ -255,6 +258,30 @@ module JamRuby
       end
     end
 
+    def set_session_controller(current_user, user)
+
+      # only allow update of session controller by the creator or the currently marked user
+
+      should_tick = false
+
+      if current_user != creator && current_user != self.session_controller
+        return should_tick
+      end
+
+      if active_music_session
+        if user
+          if active_music_session.users.exists?(user)
+            self.session_controller = user
+            should_tick = save
+          end
+        else
+          self.session_controller = nil
+          should_tick = save
+        end
+      end
+      should_tick
+    end
+
     def self.index(current_user, user_id, band_id = nil, genre = nil)
       hide_private = false
       if current_user.id != user_id
@@ -343,6 +370,7 @@ module JamRuby
       ms.legal_terms        = true
       ms.open_rsvps         = options[:open_rsvps] if options[:open_rsvps]
       ms.creator            = user
+      ms.session_controller = user
       ms.create_type        = options[:create_type]
       ms.is_unstructured_rsvp = options[:isUnstructuredRsvp] if options[:isUnstructuredRsvp]
       ms.scheduled_start    = parse_scheduled_start(options[:start], options[:timezone]) if options[:start] && options[:timezone]
diff --git a/ruby/lib/jam_ruby/models/user.rb b/ruby/lib/jam_ruby/models/user.rb
index 907cd9776..842d4beef 100644
--- a/ruby/lib/jam_ruby/models/user.rb
+++ b/ruby/lib/jam_ruby/models/user.rb
@@ -44,6 +44,8 @@ module JamRuby
 
     belongs_to :icecast_server_group, class_name: "JamRuby::IcecastServerGroup", inverse_of: :users, foreign_key: 'icecast_server_group_id'
 
+    has_many :controlled_sessions, :class_name=> "JamRuby::MusicSession", inverse_of: :session_controller, foreign_key: :session_controller_id
+
     # authorizations (for facebook, etc -- omniauth)
     has_many :user_authorizations, :class_name => "JamRuby::UserAuthorization"
 
diff --git a/web/app/assets/javascripts/dialog/sessionSettingsDialog.js b/web/app/assets/javascripts/dialog/sessionSettingsDialog.js
index 960d44cfd..92e577ecf 100644
--- a/web/app/assets/javascripts/dialog/sessionSettingsDialog.js
+++ b/web/app/assets/javascripts/dialog/sessionSettingsDialog.js
@@ -66,6 +66,20 @@
         $('#session-settings-fan-access').val('listen-chat-band');
       }
 
+      var $controllerSelect = $('#session-settings-master-mix-controller')
+
+      $controllerSelect.empty()
+      var sessionUsers = context.SessionStore.helper.users()
+
+      $controllerSelect.append('<option value="">Any one can control the Master Mix</option>')
+      $.each(sessionUsers, function(userId, user) {
+        var selected = currentSession.session_controller_id == userId ? 'selected="selected"' : ''
+        $controllerSelect.append('<option value="' + userId + '"' + selected + '>' + user.name +'</option>')
+      })
+
+      var canEditController = currentSession.session_controller_id == context.JK.currentUserId || context.JK.currentUserId == currentSession.user_id
+      $controllerSelect.easyDropDown(canEditController ? 'enable' : 'disable')
+
       /**
       // notation files in the account screen. ugh.
       $selectedFilenames.empty();
@@ -84,10 +98,12 @@
       context.JK.dropdown($('#session-settings-language'));
       context.JK.dropdown($('#session-settings-musician-access'));
       context.JK.dropdown($('#session-settings-fan-access'));
+      context.JK.dropdown($('#session-settings-master-mix-controller'));
 
       var easyDropDownState = canPlayWithOthers.canPlay ? 'enable' : 'disable'
       $('#session-settings-musician-access').easyDropDown(easyDropDownState)
       $('#session-settings-fan-access').easyDropDown(easyDropDownState)
+
     }
 
     function addNotation(notation) {
@@ -121,6 +137,7 @@
       data.name = $('#session-settings-name').val();
       data.description = $('#session-settings-description').val();
       data.language = $('#session-settings-language').val();
+      data.session_controller = $('#session-settings-master-mix-controller').val()
 
       // musician access
       var musicianAccess = $('#session-settings-musician-access').val();
@@ -148,7 +165,13 @@
         data.fan_chat = true;
       }
       
-      rest.updateSession($('#session-settings-id').val(), data).done(settingsSaved);
+      rest.updateSession($('#session-settings-id').val(), data).done(settingsSaved)
+      .done(function(response) {
+          context.SessionActions.updateSession.trigger(response);
+        })
+      .fail(function() {
+          app.notify({title: "Can't Update", text: "Unable to update session settings."})
+        })
 
       return false;
     }
diff --git a/web/app/assets/javascripts/faderHelpers.js b/web/app/assets/javascripts/faderHelpers.js
index 6d573a2c8..8de5a50b8 100644
--- a/web/app/assets/javascripts/faderHelpers.js
+++ b/web/app/assets/javascripts/faderHelpers.js
@@ -23,7 +23,14 @@
     var $fader = $(this);
     var floaterConvert = $fader.data('floaterConverter')
     var sessionModel = window.JK.CurrentSessionModel || null;
-    
+
+    /**
+    if(!$fader.data('has-session-control')) {
+      var sessionControllerName = $fader.data('session-controller-name');
+      window.JK.prodBubble($fader, 'not-session-controller', {sessionControllerName:sessionControllerName}, {positions:['left', 'right'], offsetParent: $fader.closest('.top-parent'), duration:12000})
+      return false;
+    }*/
+
     var mediaControlsDisabled = $fader.data('media-controls-disabled');
     if(mediaControlsDisabled) {
       var mediaTrackOpener = $fader.data('media-track-opener');
@@ -173,7 +180,14 @@
     var mediaControlsDisabled = $draggingFaderHandle.data('media-controls-disabled');
     var mediaTrackOpener = $draggingFaderHandle.data('media-track-opener');
     var sessionModel = window.JK.CurrentSessionModel || null;
-    
+
+    /**
+    if(!$draggingFaderHandle.data('has-session-control')) {
+      var sessionControllerName = $draggingFaderHandle.data('session-controller-name');
+      window.JK.prodBubble($draggingFaderHandle, 'not-session-controller', {sessionControllerName:sessionControllerName}, {positions:['left', 'right'], offsetParent: $draggingFaderHandle.closest('.top-parent'), duration:12000})
+      return false;
+    }*/
+
     if(mediaControlsDisabled) {
       return false;
     }
@@ -267,16 +281,34 @@
         throw ("renderFader: userOptions is required");
       }
       var renderDefaults = {
-        faderType: "vertical"
+        faderType: "vertical",
+        sessionController: null
       };
       var options = $.extend({}, renderDefaults, userOptions);
 
+      var sessionCanControl = true
+      var sessionControllerName = null
+      if(userOptions.sessionController) {
+        if(!userOptions.sessionController.can_control) {
+          sessionCanControl = false
+          console.log("userOptions.sessionController", userOptions.sessionController)
+          sessionControllerName = userOptions.sessionController.session_controller.name
+        }
+      }
+
       selector.find('div[data-control="fader"]')
         .data('media-controls-disabled', selector.data('media-controls-disabled'))
         .data('media-track-opener', selector.data('media-track-opener'))
         .data('showHelpAboutMediaMixers', selector.data('showHelpAboutMediaMixers'))
         .data('floaterConverter', floaterConverter)
         .data('snap', userOptions.snap)
+        .data('has-session-control', sessionCanControl)
+        .data('session-controller-name', sessionControllerName)
+
+
+      if(userOptions.sessionController) {
+
+      }
 
       selector.find('div[data-control="fader-handle"]').draggable({
         drag: onFaderDrag,
@@ -289,6 +321,8 @@
         .data('showHelpAboutMediaMixers', selector.data('showHelpAboutMediaMixers'))
         .data('floaterConverter', floaterConverter)
         .data('snap', userOptions.snap)
+        .data('has-session-control', sessionCanControl)
+        .data('session-controller-name', sessionControllerName)
 
       // Embed any custom styles, applied to the .fader below selector
       if ("style" in options) {
diff --git a/web/app/assets/javascripts/react-components/SessionMixerBtn.js.jsx.coffee b/web/app/assets/javascripts/react-components/SessionMixerBtn.js.jsx.coffee
index c19e4d24f..056e1202d 100644
--- a/web/app/assets/javascripts/react-components/SessionMixerBtn.js.jsx.coffee
+++ b/web/app/assets/javascripts/react-components/SessionMixerBtn.js.jsx.coffee
@@ -4,7 +4,17 @@ context = window
 
   openDialog: (e) ->
     e.preventDefault()
-    context.JK.app.layout.showDialog('session-master-mix-dialog')
+
+    sessionController = context.SessionStore.helper.sessionController()
+
+    # does this user have access to control the master mixer?
+
+    if sessionController.can_control
+      context.JK.app.layout.showDialog('session-master-mix-dialog')
+    else
+      sessionControllerName = sessionController.session_controller?.name
+      $node = $(this.getDOMNode())
+      window.JK.prodBubble($node, 'not-session-controller', {sessionControllerName:sessionControllerName}, {positions:['bottom'], offsetParent: $node.closest('.top-parent'), duration:12000})
 
   render: () ->
     `<a className="session-mixer button-grey left" onClick={this.openDialog}>
diff --git a/web/app/assets/javascripts/react-components/SessionTrackGain.js.jsx.coffee b/web/app/assets/javascripts/react-components/SessionTrackGain.js.jsx.coffee
index c4d1c6123..000d176c7 100644
--- a/web/app/assets/javascripts/react-components/SessionTrackGain.js.jsx.coffee
+++ b/web/app/assets/javascripts/react-components/SessionTrackGain.js.jsx.coffee
@@ -2,6 +2,7 @@ context = window
 logger = context.JK.logger
 ChannelGroupIds = context.JK.ChannelGroupIds
 CategoryGroupIds = context.JK.CategoryGroupIds
+MIX_MODES = context.JK.MIX_MODES
 
 @SessionTrackGain = React.createClass({
 
@@ -20,6 +21,8 @@ CategoryGroupIds = context.JK.CategoryGroupIds
     groupId = $target.data('groupId')
     mixers = @state.mixers.mixer
 
+
+
     # if this is a media track, jam track , or media category, affect volume of both mixer and opposing mixer
     if @state.mixers.mixer.group_id == ChannelGroupIds.MediaTrackGroup || @state.mixers.mixer.group_id == ChannelGroupIds.JamTrackGroup || ((@state.mixers.mixer.group_id == ChannelGroupIds.MonitorCatGroup || @state.mixers.mixer.group_id == ChannelGroupIds.MasterCatGroup) && @state.mixers.mixer.name == CategoryGroupIds.MediaTrack)
       MixerActions.faderChanged(data, [@state.mixers.mixer, @state.mixers.oppositeMixer], @props.gainType)
@@ -47,13 +50,18 @@ CategoryGroupIds = context.JK.CategoryGroupIds
     if !$root.is('.track-gain')
       logger.error("unknown root node")
 
-    context.JK.FaderHelpers.renderFader2($root, {faderType: 'vertical'});
-
     # Initialize gain position
     mixer = @state.mixers?.mixer
     if mixer && $.isArray(mixer)
       mixer = mixer[0]
 
+    sessionController = null
+    if mixer.mode == MIX_MODES.MASTER
+      # sessionController is only relevant for master mode
+      sessionController = this.props.sessionController
+
+    context.JK.FaderHelpers.renderFader2($root, {faderType: 'vertical', sessionController:sessionController});
+
     MixerActions.initGain(mixer)
 
     # watch for fader change events
diff --git a/web/app/assets/javascripts/react-components/SessionTrackVolumeHover.js.jsx.coffee b/web/app/assets/javascripts/react-components/SessionTrackVolumeHover.js.jsx.coffee
index fe0eba212..8d41f2017 100644
--- a/web/app/assets/javascripts/react-components/SessionTrackVolumeHover.js.jsx.coffee
+++ b/web/app/assets/javascripts/react-components/SessionTrackVolumeHover.js.jsx.coffee
@@ -24,10 +24,13 @@ ptrCount = 0
     newMixers = mixers.refreshMixer(@state.mixers)
 
     newMixers = {} unless newMixers?
-    this.setState({mixers: newMixers})
+    sessionController = sessionMixers.session.sessionController()
+    logger.debug("session controller", sessionController)
+
+    this.setState({mixers: newMixers, sessionController: sessionController})
 
   getInitialState: () ->
-    {mixers: this.props.mixers, ptr: "STVH#{ptrCount++}" }
+    {mixers: this.props.mixers, ptr: "STVH#{ptrCount++}", sessionController: window.SessionStore.helper.sessionController()}
 
   handleMute: (e) ->
     e.preventDefault()
@@ -85,7 +88,7 @@ ptrCount = 0
           <div>Volume</div>
           <div>{volume_left}dB</div>
         </div>
-        <SessionTrackGain mixers={this.state.mixers} gainType={this.props.gainType} />
+        <SessionTrackGain mixers={this.state.mixers} gainType={this.props.gainType} sessionController={this.state.sessionController} />
         <div className={classes} data-control="mute" data-mixer-id={muteMixerId} onClick={this.handleMute}/>
 
         <input type="checkbox" name="mute"/>
diff --git a/web/app/assets/javascripts/react-components/helpers/SessionHelper.js.coffee b/web/app/assets/javascripts/react-components/helpers/SessionHelper.js.coffee
index 460aa98e8..50a129972 100644
--- a/web/app/assets/javascripts/react-components/helpers/SessionHelper.js.coffee
+++ b/web/app/assets/javascripts/react-components/helpers/SessionHelper.js.coffee
@@ -18,6 +18,14 @@ context = window
     else
       []
 
+  users: () ->
+    found = {}
+
+    for participant in @participants()
+      found[participant.user.id] = participant.user
+
+    found
+
   otherParticipants: () ->
     others = []
     for participant in @participants()
@@ -26,6 +34,26 @@ context = window
       others.push(participant) unless myTrack
     others
 
+  sessionController: () ->
+    info = {}
+
+    # XXX testing:
+    info["can_control"] = false
+    info["session_controller"] = @participants()[0].user
+
+    if @session
+      if @session.session_controller_id == null
+        info['session_controller'] = null
+        info['can_control'] = true
+      else
+        for participant in @participants()
+          if participant.user.id == @session.session_controller_id
+            info['session_controller'] = participant.user
+            info['can_control'] = participant.user.id == context.JK.currentUserId
+            break
+
+    info
+
   # if any participant has the metronome open, then we say this session has the metronome open
   isMetronomeOpen: () ->
     @session? && @session.metronome_active
diff --git a/web/app/assets/stylesheets/client/help.css.scss b/web/app/assets/stylesheets/client/help.css.scss
index 7082d7d27..2e7ca51d6 100644
--- a/web/app/assets/stylesheets/client/help.css.scss
+++ b/web/app/assets/stylesheets/client/help.css.scss
@@ -60,6 +60,11 @@ body.jam, body.web, .dialog{
         }
       }
 
+      .larger-text {
+        margin:10px;
+        font-size:12px;
+        line-height:125%;
+      }
 
 
 
diff --git a/web/app/controllers/api_music_sessions_controller.rb b/web/app/controllers/api_music_sessions_controller.rb
index c7433ea5a..9fcb0bf7b 100644
--- a/web/app/controllers/api_music_sessions_controller.rb
+++ b/web/app/controllers/api_music_sessions_controller.rb
@@ -171,7 +171,7 @@ class ApiMusicSessionsController < ApiController
   end
 
   def update
-    @music_session = MusicSessionManager.new.update(
+    @music_session = MusicSessionManager.new.update(current_user,
       @music_session.music_session,
       params[:name],
       params[:description],
@@ -180,14 +180,16 @@ class ApiMusicSessionsController < ApiController
       params[:musician_access],
       params[:approval_required],
       params[:fan_chat],
-      params[:fan_access])
+      params[:fan_access],
+      params[:session_controller])
 
     if @music_session.errors.any?
       # we have to do this because api_session_detail_url will fail with a bad @music_session
       response.status = :unprocessable_entity
       respond_with @music_session
     else
-      respond_with @music_session, responder: ApiResponder, :location => api_session_detail_url(@music_session)
+      @music_session = @music_session.active_music_session
+      respond_with_model(@music_session)
     end
   end
 
@@ -573,7 +575,6 @@ class ApiMusicSessionsController < ApiController
     end
   end
 
-
   def jam_track_open
     unless @music_session.users.exists?(current_user)
       raise JamPermissionError, ValidationMessages::PERMISSION_VALIDATION_ERROR
diff --git a/web/app/views/api_music_sessions/session_controller.rabl b/web/app/views/api_music_sessions/session_controller.rabl
new file mode 100644
index 000000000..e34b6943d
--- /dev/null
+++ b/web/app/views/api_music_sessions/session_controller.rabl
@@ -0,0 +1,3 @@
+object @music_session
+
+extends "api_music_sessions/show"
\ No newline at end of file
diff --git a/web/app/views/api_music_sessions/show.rabl b/web/app/views/api_music_sessions/show.rabl
index 39a71810c..61067a716 100644
--- a/web/app/views/api_music_sessions/show.rabl
+++ b/web/app/views/api_music_sessions/show.rabl
@@ -37,12 +37,17 @@ else
       end
   end
 
-  node :share_url do |music_session|
+  node do |music_session|
+    session_props = {}
     unless music_session.music_session.share_token.nil?
-      share_token_url(music_session.music_session.share_token.token)
+      session_props[:share_url] = share_token_url(music_session.music_session.share_token.token)
     end
+
+    session_props[:session_controller_id] = music_session.music_session.session_controller_id
+    session_props
   end
 
+
   child(:connections => :participants) {
     collection @music_sessions, :object_root => false
     attributes :ip_address, :client_id, :joined_session_at, :audio_latency, :id, :metronome_open
diff --git a/web/app/views/api_music_sessions/update.rabl b/web/app/views/api_music_sessions/update.rabl
new file mode 100644
index 000000000..e34b6943d
--- /dev/null
+++ b/web/app/views/api_music_sessions/update.rabl
@@ -0,0 +1,3 @@
+object @music_session
+
+extends "api_music_sessions/show"
\ No newline at end of file
diff --git a/web/app/views/clients/_help.html.slim b/web/app/views/clients/_help.html.slim
index ba3dc8ceb..d5bef7834 100644
--- a/web/app/views/clients/_help.html.slim
+++ b/web/app/views/clients/_help.html.slim
@@ -222,6 +222,16 @@ script type="text/template" id="template-help-media-controls-disabled"
   | Only the person who opened the recording can control the volume levels.
   | {% } %}
 
+
+script type="text/template" id="template-help-not-session-controller"
+  .not-session-controller.larger-text
+    | This feature controls the master mix for the session, which is used to set the mix levels for recordings and session broadcasts,
+    | &nbsp;so changes to the master mix affect all musicians in the session.
+    | &nbsp;Only {{data.sessionControllerName}} has control of the master mix for this session.
+    br
+    br
+    | If you want to change the personal mix – i.e. the mix/levels that you personally hear – you can use the volume sliders on each track on the session screen to do this, and it won’t affect what other musicians in the session hear, so you can do this safely.
+
 script type="text/template" id="template-help-jamtrack-controls-disabled"
   | During a recording, volume and mute controls for JamTracks are disabled.  So, get the session volume levels right before starting the recording.
 
diff --git a/web/app/views/clients/_sessionSettings.html.haml b/web/app/views/clients/_sessionSettings.html.haml
index abd85514e..7aeaf5dd0 100644
--- a/web/app/views/clients/_sessionSettings.html.haml
+++ b/web/app/views/clients/_sessionSettings.html.haml
@@ -35,6 +35,11 @@
               %option{:value => "#{language[:id]}"}
                 = language[:label]
 
+        .clearall.left.w20.ib.mb10
+          Mix Controller:
+        .right.w75.ib.mb10
+          %select{:name => "master_mix_controller", :id => "session-settings-master-mix-controller"}
+
         .clearall.left.w20.ib.mb10
           Musician Access:
         .right.w75.ib.mb10
diff --git a/web/config/routes.rb b/web/config/routes.rb
index cb96586fe..48755c292 100644
--- a/web/config/routes.rb
+++ b/web/config/routes.rb
@@ -227,6 +227,7 @@ SampleApp::Application.routes.draw do
     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
+    match '/sessions/:id/session_controller' => 'api_music_sessions#session_controller', :via => :post
 
     # music session tracks
     match '/sessions/:id/tracks' => 'api_music_sessions#track_create', :via => :post
diff --git a/web/lib/music_session_manager.rb b/web/lib/music_session_manager.rb
index 792fe1200..81b52db49 100644
--- a/web/lib/music_session_manager.rb
+++ b/web/lib/music_session_manager.rb
@@ -67,7 +67,7 @@ class MusicSessionManager < BaseManager
   end
 
   # Update the session. If a field is left out (meaning, it's set to nil), it's not updated.
-  def update(music_session, name, description, genre, language, musician_access, approval_required, fan_chat, fan_access)
+  def update(current_user, music_session, name, description, genre, language, musician_access, approval_required, fan_chat, fan_access, session_controller_id)
 
     music_session.name = name unless name.nil?
     music_session.description = description unless description.nil?
@@ -77,7 +77,15 @@ class MusicSessionManager < BaseManager
     music_session.approval_required = approval_required unless approval_required.nil?
     music_session.fan_chat = fan_chat unless fan_chat.nil?
     music_session.fan_access = fan_access unless fan_access.nil?
+    session_controller = User.find(session_controller_id) if session_controller_id.present?
+    should_tick = music_session.set_session_controller(current_user, session_controller)
     music_session.save
+
+    if should_tick && music_session.active_music_session
+      music_session.active_music_session.tick_track_changes
+      Notification.send_tracks_changed(music_session.active_music_session)
+    end
+
     music_session
   end