message: removing 'let' from test code
diff: @@ -56,7 +56,7 @@ define(["Tone/core/Tone"], function (Tone) {
  buffer.getValueAtTime = function(time){
  var ret = [];
  var sample = Math.round(time * buffer.context.sampleRate);
  - for (let i = 0; i < buffer.numberOfChannels; i++){
  + for (var i = 0; i < buffer.numberOfChannels; i++){
  ret[i] = buffer.getChannelData(i)[sample];
  }
  if (ret.length === 1){
  