Complete all songs with a 'Platinum' rank in each venue in Showtime mode to unlock the 'Cheat Collection 4' option. Then, select the 'Cheats' option at the 'Extras Menu', select 'Cheat Collection 4', then enter one of the following codes to unlock the corresponding cheat option. A sound will confirm correct code entry.

Tough Audio Crowd: Press Circle, L1, L2, R1, R2, Right, Right, Down.
Pirate Crowd: Press Down, L2(2), R2(2), Square, Circle, Square.
Robot Crowd: Press L3, Down(2), R1, Circle, Square, Circle, Square.
Zombie Crowd: Press Square(2), Circle(2), Up, Right(2), Up.
Alien Crowd: Press Up(2), Down, Circle(2), L2, R2, Square.