let context;
  let request;
  let source;

  try {
    context = new AudioContext();
    request = new XMLHttpRequest();
    request.open("GET","http://jplayer.org/audio/mp3/RioMez-01-Sleep_together.mp3",true);
    request.responseType = "arraybuffer";

    request.onload = function() {
      context.decodeAudioData(request.response, function(buffer) {
        source = context.createBufferSource();
        source.buffer = buffer;
        source.connect(context.destination);
        // auto play
        source.start(0); // start was previously noteOn
      });
    };

    request.send();

  } catch(e) {
    alert('web audio api not supported');
  }