Marty O’Donnell and Michael Salvatori wrote a ton of music for the Halo franchise. More than six hours of it is in my iTunes, and that’s not even close to all of it.
Of all the music for Halo Marty wrote, one soundtrack rises above all the rest: Halo 3: ODST.
ODST gets a lot of hate for the campaign, the multiplayer, or both. But who cares, because the music is awesome.
Marty went in a completely different direction with ODST. He (mostly) replaced the electric guitar with a saxophone, of all things, mirroring the film noir aspects of ODST’s story. Most of the voices are gone – certainly the heavy Gregorian chant influence is missing. The piano is still there, perhaps a reminder of Halo 3, and that trademark tribal percussion is present too.