Co-Op Guitars Unlocks
[Submitted by: TomCat ]
Unlockable Basses list in Co-Op mode:

Gibson SG Bass	Beat 10 Songs
Gibson Grabber	Beat 20 Songs
Gibson Thunderbird	Beat 30 Songs
Gibson Les Paul and skin	Beat 40 Songs
Hofner Bass	Beat every song
Lava Pearl Musicman Stingray	Get 5 stars on at least 10 songs
Cream SG	Get 5 stars on 20 songs
Natural Sunburst Gibson Thunderbird Bass	Get 5 stars on every co-op mode song (stacks with below)
Natural Maple Gibson Grabber Bass	Get 4 stars on all co-op mode songs

Green Button trick
[Submitted by: ShadowSky ]
Just put a rubber band around the green button,play it on hard so you don't have to push 5 buttons at a time. Try it!

Scorpion
[Submitted by: Tempest ]
Ok you go to the main menu and hit this code.
Yellow,blue,blue,red,orange,blue,Yellow,green,green,orange,red,red,red

Then you count 8 beats on any song under easy and on the 8th beat pause the game and press the orange, yellow and red button at the same time.

Then finish the song with 95% more and you will unlock Scorpion from MortalKombat as your character!!!

Guitar Hero 2 Cheat Code Hints!!!
[Submitted by: BusyBee ]
Master Unlock code is blue yellow orange red orange yellow red yellow red yellow red yellow red yellow red yellow enter this code at the start menu if entered correctly you will hear a guitar rif and it will say unlocked! You have to enter this code fast for it to work, if you do not enter it fast enough it will not work! It unlocks everything but disables auto save, so you will have to enter it everytime you reset.

Having a hard time getting from medium to hard? Go into practice mode and play different songs on hard, instead of placing your fingers on the first four frets place them on the 2nd through 5th. You will have to learn which fingers play which keys when you slide down to hit the orange fret. Ignore the green fret while you learn these keys, Before you know it you will retrain your fingers to play these keys! Then you will have no problem going back to the first four and easily sliding down and playing the 2nd hand position to hit those orange keys! I thought hard was impossible until I learned the second hand position and within a week I am on expert! Good luck!

HYPER SPEED
[Submitted by: alkaroth ]
Hyper speed is easy so here what it does it might go fast a litttle bit but it makes lesser notes in that song it is going fast thats why.Just press blue,orange,yellow,orange,blue,orange,yellow,yellow.Do that fast and hyper speed should work if it did not try a few more times you will get and hyper speed will work good luck doing that cheat.

Performance mode
From main menu, quickly press:
Yellow(2), Blue, Yellow(2), Orange, Yellow(2)
A message will appear if you entered correctly. In this mode, everything except for the performance,disappears. You can repeat this code to disable its effect.
PAL version, quickly press:
Yellow(2), Orange, Yellow(2), Blue, Yellow(2) from main menu.

Hyper Speed mode
From main menu, quickly press:
Orange, Blue, Orange, Yellow, Orange, Blue, Orange, Yellow
A message will appear if you entered correctly. In this mode, the frets will move faster. You can repeat this code to disable its effect.
PAL version, quickly press:
Yellow, Orange, Blue, Orange, Yellow, Orange, Blue, Orange from main menu.

Full Rock meter
You can now start a song and max out the Rock meter, then reset the song to start with a full rock meter.

Horse head
From main menu, quickly press:
Blue, Orange(2), Blue, Orange(2), Blue, Orange(2), Blue
If you entered correctly, a message will appear. Repeat this code to disable its effect.
PAL version, quickly press:
Orange(2), Blue, Orange(2), Blue, Orange(2), Blue, Orange at the main menu.

Bonus Guitars
Complete the listed task to unlock the listed guitar at the shop:

Battle Axe	Complete the game on the Expert difficulty setting.
Casket	Complete the game on the Medium difficulty setting.
Fish	Complete the game on the Easy difficulty setting.
Eyeball	Get a five star rank on all songs on the Hard difficulty setting.
Snaketapus	Complete the game on the Hard difficulty setting.
The Log	Get a five star rank on all songs on the Expert difficulty setting.
U.S.A.	Get a five star rank on all songs on the Easy difficulty setting.
Viking	Get a five star rank on all songs on the Medium difficulty setting.

Monkey Headed Audience
From the main menu, press:
Orange, Blue, Yellow(2), Orange, Blue, Yellow(2)
If you entered correctly, a message will appear. Repeat this code to disable its effect.
PAL version, quickly press:
Yellow(2), Blue, Orange, Yellow(2), Blue, Orange from main menu.

Bonus Song List
Complete the listed task on the Medium or higher difficulty setting to unlock the listed song:

Tonight, I'm Gonna Rock You Tonight	Complete the first set and do the encore.
Carry On My Wayward Son	Complete the second set and do the encore.
War Pigs	Complete the third set and do the encore.
Sweet Child O' Mine	Complete the fourth set and do the encore.
Last Child	Complete the fifth set and do the encore.
Stop	Complete the sixth set and do the encore.
YYZ	Complete the seventh set and do the encore.
Free Bird	Complete the eighth set and do the encore.

Playing the Scythe with others
Unlock the Grim Ripper and select him.
Select another character whose alternate outfit is already unlocked and they will have the Scythe. ***Clive Winston and Xavier Stone do not have an unlockable outfits and cannot do this trick.

Ranks

One star	Get 64% or less of the notes correct.
Two stars	Get 65% to 76% of the notes correct.
Three stars	Get 76% to 88% of the notes correct.
Four stars	Get 88% to 96% of the notes correct.
Five stars	Get at least 96% of the notes correct.
Gold five stars	Get every note correct on a song.

Eyeball Headed Audience
From main menu, quickly press:
Blue, Orange, Yellow, Orange, Yellow, Orange, Blue
If you entered correctly, a message will appear. Repeat this code to disable its effect.
PAL version: Yellow, Orange, Blue, Orange, Blue, Orange, Yellow from main menu.

PAL version Cheat mode
Unlock all bonuses:
From main menu, quickly press:
Blue, Yellow, Orange(2), Yellow, Blue, Yellow, Blue, Yellow, Blue, Yellow, Blue, Yellow, Blue, Yellow .

Guitarist uses Air Guitar
From main menu, quickly press:
Yellow(2), Blue, Orange, Yellow, Blue
If you entered correctly, a message will appear. Repeat this code to disable its effect. PAL version, quickly press: Blue, Yellow, Orange, Blue, Yellow(2) from main menu.

Bonus basses
Complete stated number of songs in Co-Op mode to unlock the listed bass at the shop for Co-Op mode:

Gibson Grabber	20 songs
Gibson SG	10 songs
Gibson Thunderbird	30 songs
Lava Pear Musician Stingray	21 songs with a five star rank on the Hard difficulty setting

Flaming Head
From main menu, quickly press:
Orange, Yellow, Orange(2), Yellow, Orange, Yellow(2)
A message will appear if you entered correctly. Repeat this code to disable its effect. PAL version, quickly press Yellow(2), Orange, Yellow, Orange(2), Yellow, Orange from main menu.

Pro Face-Off mode
This mode allows two players to play all the notes. to do it you must complete the game on the Medium difficulty setting to unlock Pro Face-Off mode.

Grim Ripper plays Gibson Les Paul
Unlock the Grim Ripper.
Select Grim Ripper as your guitarist in Career mode, then exit Career mode.
Go to Quick Play mode, choose any song on any difficulty level. You can either finish the song or quit once it has started.
Now, go back to Career mode and the Grim Ripper will be playing the Gibson Les Paul with the Cherry Sunburst Classic skin. To make him play the Scythe again, simply select it in the Change Guitar menu.