added new view controllers for artists and albums.  Changed button bar in now playingadded new view controllers for artists and albums.  Changed button bar in now playingadded new view controllers for artists and albums.  Changed button bar in now playingadded new view controllers for artists and albums.  Changed button bar in now playingadded new view controllers for artists and albums.  Changed button bar in now playingadded new view controllers for artists and albums.  Changed button bar in now playingadded new view controllers for artists and albums.  Changed button bar in now playingadded new view controllers for artists and albums.  Changed button bar in now playingadded new view controllers for artists and albums.  Changed button bar in now playing