diff --git a/lib/jam_ruby/models/music_session_history.rb b/lib/jam_ruby/models/music_session_history.rb
index c09a76be2..7c83e9e4f 100644
--- a/lib/jam_ruby/models/music_session_history.rb
+++ b/lib/jam_ruby/models/music_session_history.rb
@@ -34,6 +34,14 @@ module JamRuby
       return query
     end
 
+    def unique_users
+      User
+      .joins(:music_session_user_histories)
+      .group("users.id")
+      .order("users.id")
+      .where(%Q{ music_sessions_user_history.music_session_id = '#{music_session_id}'})
+    end
+
     def self.save(music_session)
       session_history = MusicSessionHistory.find_by_music_session_id(music_session.id)
 
diff --git a/lib/jam_ruby/models/user.rb b/lib/jam_ruby/models/user.rb
index d580c544c..23f888e6d 100644
--- a/lib/jam_ruby/models/user.rb
+++ b/lib/jam_ruby/models/user.rb
@@ -94,6 +94,7 @@ module JamRuby
 
     # session history
     has_many :music_session_histories, :foreign_key => "user_id", :class_name => "JamRuby::MusicSessionHistory"
+    has_many :music_session_user_histories, :foreign_key => "user_id", :class_name => "JamRuby::MusicSessionUserHistory"
 
     # saved tracks
     has_many :recorded_tracks, :foreign_key => "user_id", :class_name => "JamRuby::RecordedTrack", :inverse_of => :user
diff --git a/spec/factories.rb b/spec/factories.rb
index f91a3e9f0..ddac6d64b 100644
--- a/spec/factories.rb
+++ b/spec/factories.rb
@@ -30,8 +30,29 @@ FactoryGirl.define do
     approval_required false
     musician_access true
     legal_terms true
+    association :creator, :factory => :user
+  end
 
-    after(:create) { |session| MusicSessionHistory.save(session) }
+  factory :music_session_history, :class => JamRuby::MusicSessionHistory do
+    ignore do
+      music_session nil
+    end
+
+    music_session_id { music_session.id }
+    description { music_session.description }
+    user_id { music_session.user_id }
+    band_id { music_session.band_id }
+  end
+
+  factory :music_session_user_history, :class => JamRuby::MusicSessionUserHistory do
+    ignore do
+      history nil
+      user nil
+    end
+
+    music_session_id { history.music_session_id }
+    user_id { user.id }
+    sequence(:client_id) { |n| "Connection #{n}" }
   end
 
   factory :connection, :class => JamRuby::Connection do
diff --git a/spec/jam_ruby/models/music_session_history_spec.rb b/spec/jam_ruby/models/music_session_history_spec.rb
new file mode 100644
index 000000000..260917687
--- /dev/null
+++ b/spec/jam_ruby/models/music_session_history_spec.rb
@@ -0,0 +1,28 @@
+require 'spec_helper'
+
+describe MusicSessionHistory do
+
+  let(:some_user) { FactoryGirl.create(:user) }
+  let(:music_session) { FactoryGirl.create(:music_session) }
+  let(:history) { FactoryGirl.create(:music_session_history, :music_session => music_session) }
+  let(:user_history1) { FactoryGirl.create(:music_session_user_history, :history => history, :user => music_session.creator) }
+  let(:user_history2) { FactoryGirl.create(:music_session_user_history, :history => history, :user => some_user) }
+
+  it "create" do
+    history.description.should eql(music_session.description)
+  end
+
+  it "unique users" do
+    user_history1.should_not be_nil
+    user_history2.should_not be_nil
+    users = history.unique_users
+
+    users.length.should eql(2)
+
+    users.include?(some_user).should be_true
+    users.include?(music_session.creator).should be_true
+  end
+
+end
+
+
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index e8c095186..eeab8e42e 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -17,6 +17,9 @@ require 'spork'
 require 'database_cleaner'
 require 'factories'
 
+# uncomment this to see active record logs
+# ActiveRecord::Base.logger = Logger.new(STDOUT) if defined?(ActiveRecord::Base)
+
 include JamRuby
 
 # manually register observers