here you go dude: Unlock All Songs
Press Red, Yellow, Blue, Red(2), Blue(2), Red, Yellow, Blue to unlock all songs. Alternately, press Y, B, X, Y(2), X(2), Y, B, X on a controller. Note: This code also disables achievements and online features. -From: Geramie Edwards
Select Venue Screen
Press Blue, Orange(2), Blue, Yellow, Blue, Orange(2), Blue, Yellow to unlock all venues. Alternately, press X, LB(2), X, B, X, LB(2), X, B on a controller. Note: This code also disables online features.
New Venues
Press Red(4), Yellow(4) to unlock new venues. Alternately, press Y(4), B(4) on a controller.
Awesome Detection
Press Yellow, Blue, Orange, Yellow, Blue, Orange, Yellow, Blue, Orange. Alternately, press B, X, LB, B, X, LB, B, X, LB on a controller.
Breakneck Speed
Press Orange, Yellow, Orange, Yellow, Blue, Orange(2), Blue. Alternately, press LB, Y, LB, Y, X, LB(2), X on a controller. This code increases the scroll speed of the instrument tracks.
Performance Mode
Press Blue(2), Red(2), Yellow(2), Blue(2). Alternately, press X(2), Y(2), B(2), X(2) on a controller. Performance mode removes the track display.
Stage Mode
Press Blue, Yellow, Red, Blue, Yellow, Red, Blue, Yellow, Red. Alternately, press X, B, Y, X, B, Y, X, B, Y on a controller. Stage mode tweaks the game for live, public performances. Note: This code also disables achievements, failing songs, pausing the game, and online features.
BTW go to extras, modify game, then type in your own code ; )