function prependSong(song) {
    /*
    Ensures we have a songs array to push to.
    */
    if (_config2.default.songs == undefined) {
      _config2.default.songs = [];
    }

    _config2.default.songs.unshift(song);

    if (_config2.default.shuffle_on) {
      _config2.default.shuffle_list.unshift(song);
    }

    if (_soundcloud2.default.isSoundCloudURL(song.url)) {
      _soundcloud2.default.resolveIndividualStreamableURL(song.url, null, _config2.default.songs.length - 1, _config2.default.shuffle_on);
    }

    return 0;
  }
Adds a song to the beginning of the config array.
This will allow Amplitude to play the song in a
playlist type setting.

Public Accessor: Amplitude.addSong( song_json )

@access public
@param {object} song 	- JSON representation of a song.
@returns {number} New index of the song (0)