Cheats

In the options menu you will see a cheats section at the bottom. Inside the Cheats Menu hit "Enter New Cheat" then enter the desired code. (Note: Do not strum)
Password Effect
Blue, Red, Yellow, Yellow, Yellow, Yellow, Yellow, Green Aaron
Red, Red, Blue, Yellow, Green, Green, Green, Yellow Air Instruments
G, G, R, R, Y, R, Y, B Always slide (all notes connected by purple line)
Yellow, Green, Red, Blue, Blue, Blue, Blue, Red Auto Kick
G, R, G, B, R, R, Y, B Change Flame Color
B, R, R, G, R, G, R, Y Change Gem Color
Green, Blue, Red, Yellow, Yellow, Red, Green, Green Hyperspeed
Green, Red, Yellow, Yellow, Yellow, Blue, Blue, Green Invisible Rocker
Blue, Red, Blue, Blue, Yellow, Yellow, Yellow, Green Johnny Viper
Green, Red, Blue, Green, Red, Blue, Blue, Green Nick
Yellow, Yellow, Blue, Red, Blue, Green, Red, Red Preformance mode
Blue, Red, Green, Green, Yellow, Yellow, Yellow, Green Rina
R, R, Y, R, B, R, R, B Star Color
Y, G, R, R, G, B, R, Y Unlock AT&T Ballpark
Blue, Blue, Red, Green, Green, Blue, Blue, Yellow Unlocks all songs (Note: You must activate it in the cheats menu.)
R, G, G, Y, B, G, Y, G Vocal Fireball

Contributed By: gaara1itachi2 and frenat.
Unlockables
Unlock "Pull Me Under"

Complete the full career for any instrument, any difficulty. You play the song in the credits, and then you unlock it.

Contributed By: Llamaman2.
Unlockable Characters

All characters must be bought from the character select screen after completing the unlocking requirements.
Unlockable How to Unlock
Billy Corgan Play the song 'Today' in the band career.
Hayley Williams Play the song 'Misery Business' in the vocals career.
Ozzy Osbourne Play the Ozzfest gig in the vocals career.
Rockubot Complete the drum career.
Skeleton Complete the vocals career.
Sting Play the song 'Demolition Man' in the bass career.
Ted Nugent Beat his guitar battle in the guitar career.
Travis Barker Play the song 'Dammit' in the drum career.
Zakk Wylde Beat his guitar battle in the guitar career.