I think I just made a mess on the keyboard. Here's some info from Wikipedia on the 360 version of Guitar Hero II. (Hey, give me a break. I wanted to unlock all the PS2 songs first so it wouldn't be a spoiler.)
Bonus tracks that include "Hush" - Deep Purple, "Billion Dollar Babies" - Alice Cooper, "Rock and Roll Hoochie Koo" - Rick Derringer, "The Trooper" - Iron Maiden.
The original set list from Guitar Hero via the XLM.
Downloadable songs via the XLM.