Master code
Press Blue, Orange, Yellow, Red, Orange, Yellow, Blue, Yellow, Red, Yellow, Blue, Yellow, Red, Yellow, Blue, Yellow when your at the main menu to access every guitar, song, video, and cheat. Saving your game will be disabled, and you need to turn off the PlayStation2 to disable it.

Monkey crowd
Press Blue(2x's), Orange, Yellow, Blue(2x's), Orange, Yellow when your at the main menu.

Air guitar
Press Yellow, Blue, Yellow, Orange, Blue(2x's) when your at the main menu.

Horse head
Press Blue, Orange(2x's), Blue, Yellow, Blue, Orange(2x's), Blue, Yellow when your at the main menu.

Flame head
Press Yellow, Orange, Yellow, Orange, Yellow, Orange, Blue, Orange when your at the main menu.

Performance mode
Press Blue(2x's), Orange, Yellow(2x's), Blue, Orange, Blue when your at the main menu. Everything disappears but the performance.

Hyperspeed mode
Press Yellow, Blue, Orange(2x's), Blue, Yellow(2x's), Orange when your at the main menu. The frets will be moving faster. You can still save your game when this code is used. Repeat this code to turn it off.

Eyeball crowd
Press Yellow, Blue, Orange(3x's), Blue, Yellow when your at the main menu.

Pro Face-Off mode
Finish the game within the Hard or higher difficulty setting.

Hints & Tips

Guitars
Finish the listed task to access the matching guitar in the shop.

Axe: Complete Expert Career mode,
Casket: Complete Medium Career mode.
Eyeball: Get a "Five Star" rank on all Hard Career mode songs.
Fish: Complete Easy Career mode.
Snaketapus: Complete Hard Career mode.
The Log: Get a "Five Star" rank on all Expert Career mode songs.
USA: Get a "Five Star" rank on all Easy Career mode songs.
Viking: Get a "Five Star" rank on all Medium Career mode songs.

Encore songs
Finish the listed task to access the matching song.

18 And Life by Skid Row: Complete the first set and do the encore.

Because It's Midnight by Limozeen: Complete Amp Warmers and do the encore.

I Wanna Rock by Twisted Sister: Complete String Snappers and do the encore.

Round And Round by Ratt: Complete Return Of The Shred.

Wrathchild by Iron Maiden: Complete Relentless Riffs.

Play With Me by Extreme: Complete Furious Fretwork.

Basses
Finish the listed task to access the matching bass in the shop, which can only be used in co-op mode by the bass player with a song with a bass track.

Gibson Cream SG: Get a "Five Star" rank on 20 songs in Co-Op mode.

Gibson Grabber: Complete 20 songs in co-op mode.

Gibson Natural Maple Grabber: Get a "Four Star" or better rank on all songs in Co-Op mode.

Gibson Natural Sunburst Thunderbird: Get a "Five Star" rank on all songs in Co-Op mode.

Gibson SG: Complete 10 songs in Co-Op mode.

Gibson Thunderbird: Complete 30 songs in Co-Op mode.

Hofner: Complete all songs in Co-Op mode.

Musicman Lava Pearl Stingray: Get a "Five Star" rank on all songs in Co-Op mode.