With video-game soundtracks developing into a full-fledged genre of their own, the meticulous remixing, compiling, and production on 2004's HALO 2 heralded the trend. Reworked versions of the video game's original theme music by Michael Salvatori and Marty O'Donnell take up the bulk of the album, with an overall sound that owes a debt to contemporary electronica, New Age ambient, 1970s stadium rock, and orchestral music alike. The surging, cinematic vibe of HALO 2 's original score offsets the alternative-rock and metal acts that populate the rest of the set list.
Breaking Benjamin, for example, mix an epic, guitar-heavy attack with post-punk flourishes on the rousing "Blow Me Away," while Hoobastank, whose "Connected" is included here as a bonus track, recalls the soaring, grungy sound of early Pearl Jam. But it is the extended suite by nu-metal band Incubus that stands out. "Odyssey," split into four movements evenly spaced throughout the soundtrack, touches on prog rock, spacey jams, tribal drumming, and avant-garde jazz-funk, and makes for some of the most interesting listening here. Also of note is that HALO 2 is produced by Nile Rodgers; his slicing, high-definition sound engineering makes this carnival of music all the more enjoyable.