According to
GameSpot, a picture-happy retail employee snapped some pictures of all the songs available for purchase. With apologies for yet another bump, I present the unlockables.
Artist--Song The Acro-brats--"Laughtrack"
All That Remains--"Six"
The Amazing Royal Crowns--"Mr. Fix-It"
Anarchy Club--"Collide"
Bang Camaro--"Push Push (Lady Lightning)"
Breaking Wheel (formerly known as Artillery)--"One for the Road"
Brian Kahanek--"Gemini"
Buckethead--"Jordan"
Count Zero--"Radium Eyes"
Dethklok--"Thunder Horse"
Drist--"Arterial Black"
Every Time I Die--"The New Black"
Freezepop--"Less Talk More Rokk"
Honest Bob and the Factory-to-Dealer Incentives--"Soy Bomb"
The Last Vegas--"Raw Dog"
Made in Mexico--"Yes We Can"
Megasus--"Red Lottery"
The Neighborhoods--"Parasite"
Shadows Fall--"The Light That Blinds"
Strong Bad (of Homestar Runner)--"Trogdor"
That Handsome Devil--"Elephant Bones"
Vagiant--"FTK"
Valient Thorr--"Fall of Pangea"
Voivod--"X-Stream"
I've only heard of 6 of those bands, 2 of them are returning from the first game (new songs of course) and one of them is quite fictitious. And no DragonForce. I am left somewhat disapointed.