Enter "LETSBOOGIE" as a code. Press Fire(12), Reload, Fire(5), Reload, Fire(20), Reload, Fire(19), Reload, Fire(15), Reload, Fire(15), Reload, Fire(7), Reload, Fire(9), Reload at the main menu. Alternately, successfully complete all episodes in the Mighty Joe Jupiter Trilogy to unlock the "Music Jukebox" option at the Options screen.