www.bungie.net | halo.bungie.net | bungiestore.com
In "Quarantine Zone" when you go through the first tunnel into the big room, what's the music in the big room? It's my favorite in the entire game.
I recently played H2 through again, and this music stood out to me, I hadn't noticed it before. It uses a similar piano thingy to the one in the Halo 3 trailer.