HTML5 Basic Audio level Frequancy

<!DOCTYPE html>
<html lang="en">
<head>
  <title></title>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <link rel="stylesheet" href="//maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
  <script src="//ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>
  <script src="//maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>

  <script>
    var audio = new Audio();
    audio.src = 'music.mp3';
    audio.autoplay = true;

    var context, analyser, source;
    $(document).ready(function(){

      context = new AudioContext(); // AudioContext object instance
      analyser = context.createAnalyser(); // AnalyserNode method
      source = context.createMediaElementSource(audio);
      source.connect(analyser);
      analyser.connect(context.destination);
      loop();
    });

    function loop(){
      window.requestAnimationFrame(loop);
      fbc_array = new Uint8Array(analyser.frequencyBinCount);
      analyser.getByteFrequencyData(fbc_array);
      var output = fbc_array.toString().replace(new RegExp(',', 'g'),"<br>");
      $("#output").html(output);

    }
  </script>
</head>
<body>

<div class="container">
  <h2>Audio Levels</h2>
  <div id="output"></div>
</div>

</body>
</html>