message: correctly handles changing playbackRate after source is started
diff: @@ -369,11 +369,12 @@ define(["Tone/core/Tone", "Tone/core/Buffer", "Tone/source/Source", "Tone/source
  },
  set : function(rate){
  this._playbackRate = rate;
  - //get the current source
  - var event = this._state.get(this.now());
  - if (event && event.source){
  + //set all future sources
  + this._state.forEachFrom(this.now(), function(event){
  + if (event.source){
  event.source.playbackRate.value = rate;
  }
  + });
  }
  });
  