function setSongMetaData(index, metaData) {
    var playlist = arguments.length > 2 && arguments[2] !== undefined ? arguments[2] : null;

    /*
      Update the meta data for a song in a playlist.
    */
    if (playlist != "" && playlist != null && _config2.default.playlists[playlist] != undefined) {
      /*
        Set all of the defined meta data properties
      */
      for (var key in metaData) {
        if (metaData.hasOwnProperty(key)) {
          if (key != "url" && key != "URL" && key != "live" && key != "LIVE") {
            _config2.default.playlists[playlist].songs[index][key] = metaData[key];
          }
        }
      }
    } else {
      /*
        Update the meta data for a song.
      */
      for (var key in metaData) {
        if (metaData.hasOwnProperty(key)) {
          if (key != "url" && key != "URL" && key != "live" && key != "LIVE") {
            _config2.default.songs[index][key] = metaData[key];
          }
        }
      }
    }

    /*
      Display the updates on the screen.
    */
    _metaDataElements2.default.displayMetaData();
    _metaDataElements2.default.syncMetaData();
  }
Sets the meta data for a song in the songs array. This will set any
meta data for a song besides the URL. The URL could cause issues if the
song was playing.

Public Accessor: Amplitude.setSongMetaData()

@access public
@param {number} index					- The index of the song in the songs array.
@param {object} metaData 			- The object containing the meta data we are updating.
@param {string} playlist       - The playlist we are updating the song meta data for.