The Halo Original Soundtrack is a soundtrack for the video game Halo: Combat Evolved. Composed and produced by Martin O'Donnell and Michael Salvatori for Bungie Studios, the soundtrack was released on June 11, 2002. Most of the music from Halo: Combat Evolved is present on the CD, although some songs have been remixed by O'Donnell in medley form for "more enjoyable" listening. The first piece O'Donnell wrote, known as "Halo", became the basis for Halo's "signature sound" which has been heard in the other games of the main trilogy.
The soundtrack features a wide range of musical styles, including chanting, string orchestra, and percussion. Upon release, the soundtrack was well received by critics. Some complimented the wide range of musical styles, and most agreed that playing the game is not required to enjoy the soundtrack. A special edition of the soundtrack was released on October 28, 2003, featuring a DVD with a trailer, demo movie, and high quality music for Halo 2.