Check out Song Tapper. You tap out a beat with your space bar and it tells you what song it is (well, it gives you multiple choices of what the song might be). It recognized Billie Jean and Iron Man. It thought Iron Man might also be a song called Baby, Pull All Dat Ass Out by a group called Registered Sex Offenders. Nice.
Ahhhhhh!!!!! A library classification game!! Noooooo!!!!