yt_audio_player

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
    <audio id="youtube" autoplay controls loop></audio>
    <script type="text/javascript">
    var vid = "3r_Z5AYJJd4",
    audio_streams = {};

    $.get('https://cors-anywhere.herokuapp.com/https://www.youtube.com/get_video_info?video_id=' + vid, function(data) {
    var data = parse_str(data),
      streams = (data.url_encoded_fmt_stream_map + ',' + data.adaptive_fmts).split(',');
    console.log(streams);
    $.each(streams, function(n, s) {
      var stream = parse_str(s),
        itag = stream.itag * 1,
        quality = false;
      console.log(stream);
      switch (itag) {
        case 139:
          quality = "48kbps";
          break;
        case 140:
          quality = "128kbps";
          break;
        case 141:
          quality = "256kbps";
          break;
      }
      if (quality) audio_streams[quality] = stream.url;
    });
    console.log(audio_streams);
    $("#youtube").attr({
      src: audio_streams['128kbps']
    });
    });

    function parse_str(str) {
    return str.split('&').reduce(function(params, param) {
      var paramSplit = param.split('=').map(function(value) {
        return decodeURIComponent(value.replace('+', ' '));
      });
      params[paramSplit[0]] = paramSplit[1];
      return params;
    }, {});
    }
    </script>