Select Extras on the main menu, then Cheats and enter these codes to unlock the hidden music tracks.

Password - Effect

LOYALTY - After Hours by Nyne
MILITAIN - Anything Goes by C-N-N
CHOPPER - Blindside by Baxter
BIGBOI - Bust by Outkast
CHOCOCITY - Comp by Comp
AKIRA Dragon - House by Chiang
PLATINUMB - Get it Now by Bless
GHOSTSHELL - Koto by Chiang
GONBETRUBL - Lil Bro by Ric-A-Che
KIRKJONES - Man Up by Sticky Fingaz
RESPECT - Move! by Public Enemy
POWER - Original Gangster by Ice T
ULTRAMAG - Poppa Large by Ultramagnetic MC's