To enter codes go to the main menu, go to "Options", then "Cheats", then "Enter Cheat". Then play the following notes.

YB, GY, GY, RB, RB, RY, RY, YB, GY, GY, RB, RB, RY, RY, GY, GY, RY, RY    Air Guitar

GR, GY, YB, RB, BO, YO, RY, RB    Easy Expert (Widens timing windows, Does not work in career mode)

O,B,O,Y,O,B,O,Y    Hyperspeed

(GR) (GR) (GR) (GB) (GB) (GB) (RB) R R R (RB) R R R (RB) R R R    It makes Bret Michaels the singer

RY, RB, RO, RB, RY, GB, RY RB    Performance Mode

GR,GR,GR,RY,RY,RB,RB,YB,YO,YO,GR,GR,GR,RY,RY,RB,RB,YB,YO,YO    Precision Mode

[GRBO] [GRYB] [GRYO] [GBYO] [GRYB] [RYBO] [GRYB] [GYBO] [GRYB] [GRYO] [GRYO] [GRYB] [GRYO]    Unlock everything (no audio will play when entering this code)

YO,RB,RO,GB,RY,YO,RY,RB,GY,GY,YB,YB,YO,YO,YB,Y,R,RY,R,Y,O    Unlocks All Songs

GR, B, GR, GY, B, GY, RY, O, RY, GY, Y, GY, GR    You won’t fail any song on any difficulty. This does not work with career mode, online, or with top scores online.