To unlock new songs you must get the chipmunks to perform tricks. You know how simon does a handstand and alvin breakdances, well if you get the chipmunks to perform alot of tricks in each song you play you get to unlock a cool song. Songs you could unlock: Ho Ho Ho,Shake your groove thing,Funkytown,Only you, Just dance ( sung by the chippetes) Never gonna let you go. Also get alvin and simon to perform tricks in hard levels to unlock more songs too