- “Overall, I think this score is a bit more intimate and personal. We're telling a human story, not a cyborg story. This isn't a space opera, but a story that takes place on Earth in one city. Although the player gets to inhabit the shoes of several characters, they still primarily should feel like one person discovering the mystery that lies behind the ruins of New Mombasa.”— Martin O'Donnell to Music 4 Games
The Halo 3: ODST Original Soundtrack consists of music tracks composed by Martin O'Donnell and Michael Salvatori, is a two-disc set similar to the Halo 2: Original Soundtrack and Halo 3: Original Soundtrack.
As with the previous soundtracks, each music is made up of suites, and the suites are ordered to correspond with their in-game appearance. It was composed and produced by Marty O' Donnell and Michael Salvatori, and includes a complete 68 track listing inside. There are 17 songs on two discs.
- The movement "Orbital Drop Shock Trooper" from the Finale has a run-time of 3:43, a reference to seven and possibly the eponymous Monitor 343 Guilty Spark. Additionally "Prepare to Drop," named after the game's tagline, has a run-time of 1:17, a reference to John-117.
- Marty O'Donnell was going for more of a jazz perspective for the ODST soundtrack. Throughout the Soundtrack there are several songs that contain solo saxophone sections to add to the created atmosphere. There are two songs, however, that include electric guitar along with heavier sounding percussion to create cinematic moments in the game. These two tracks are Skyline and Traffic Jam.
- The soundtrack won several awards; the Best Original Score at the 2009 Spike Video Game Awards and Best Original Score and Sounds in the Czech Gaming Awards "Invaze 2009".
- Most of the tracks that play during Mombasa Streets have a film noir flare, due to the jazz perspective used in the soundtrack. This seems fitting, since most film noir movies are about detectives, and the Rookie, to a certain extent, can be compared to a detective.