error:
    {{playListTitle}}
    {{classes.artistPrefix + ' ' + list.tracks[currentTrack].album_artist}}
    {{list.tracks[currentTrack].track_title}}
    {{list.tracks[currentTrack].album_title}}
    {{classes.skipBackward}}
    {{classes.skipForward}}
    {{this.mediaPlayer.getPlaybackRate()}}X
    {{ currentTime }}
    {{ totalTime }}