Chaos Theory doesn't so much accompany a video game as it does mark an entirely new era of media. Video games have had soundtracks in the past, but never have they been this dignified. The Final Fantasy series, for example, has always had original music, but it contains the same scent of triviality as the dialog. Halo 2 was fitted with original music as well, but it's typical and inevitably aggravating. Still, most other games just have sound effects.
What sets Chaos Theory apart from every other recording to date is its refreshing dynamic of legitimately great music in a video game environment. Nothing similar has been done before. Ever. It is the soundtrack to a video game in the vein of a proper film score, not dissimilar to Bernard Herrmann's work with Hitchcock, but the difference is in the design. Video games are interactive, and so the music must be written accordingly. To facilitate this, Amon Tobin composed a number of initial pieces, each organized internally into four levels of stress. The tracks were then picked apart and integrated into the game (i.e. when your character stumbles onto some risky shit, the music changes to add tension). Finally, he put the pieces back together to form Chaos Theory, an intense head rush into oblivion. And what a wonderful oblivion it is.
But let's remove the concept and process entirely for a minute. This is some fucking great music. It is Amon Tobin's richest work, and incredibly aurally pleasing. "The Lighthouse" starts the album off in true Amon Tobin fashion, and "Displaced" is one of his best tracks to date; but it is "Kokubo Sosho" and "Ruthless" which exemplify one of Chaos Theory's most unique attributes. It's cohesive as a whole, yet it never repeats itself. Sure, when you take some of the songs individually, they may not match up directly to previous Amon Tobin work ("Theme From Battery" almost doesn't even sound like him and something like "Hokkaido" is definitely not better than, say, "Reanimator"), but as a whole, Chaos Theory stands individually excellent. It is like nothing else.
1. The Lighthouse
3. Theme from Battery
4. Kokubo Sosho Stealth
5. El Cargo
7. Ruthless (Reprise)
8. Kokubo Sosho Battle (adapted from Cougar Merkin)
10. The Clean Up