message: check that a param is defined
diff: @@ -52,7 +52,7 @@ define(["Tone/core/Tone", "Tone/type/Type", "Tone/core/AudioNode", "Tone/core/Ti
  */
  this._events = new Tone.Timeline(1000);
  - if (!Tone.isUndef(options.value)){
  + if (!Tone.isUndef(options.value) && this._param){
  this.value = options.value;
  }
  };
  