User blog comment:Damac1214/Black Ops II Zombies Reveal Released/@comment-3046261-20120926234316/@comment-5472968-20120927101003

You can plug it in, but the song is not actually built into the game whent that happnes. Instead, the system picks one to play over top of the other and messes up the sound quality for one of the two. So multiple song easter eggs would be nice. (I mean repeating, not different songs like Moon)