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, 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 Halos "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. Background As audio director for Bungie, Martin O'Donnell was tasked with writing the music for Halo: Combat Evolved. He had scored previous Bungie projects, including Myth: The Fallen Lords, while working for his audio company, TotalAudio, along with Michael Salvatori. O'Donnell stated that he approached the project "with fear and trepidation" and that his main influences were music he liked—"a little Samuel Barber meets Giorgio Moroder". Bungie director of cinematics Joseph Staten told O'Donnell that "the music should give a feeling of importance, weight, and sense of the 'ancient' to the visuals of Halo". O'Donnell's first piece of music, "Halo", which would become "the signature theme for Halo", was written and recorded in three days. O'Donnell convinced Alex Seropian to allow him to produce an original piece of music for the game's 1999 Macworld Conference & Expo demonstration. He drew inspiration for the theme from The Beatles' "Yesterday". O'Donnell recruited Salvatori and three other colleagues with whom he had recorded jingles—Robert Bowker, Jeffrey Morrow, and Rob Trow—to produce the "chanting monks" that open the piece. Originally, he had intended the Qawwali accents to be sung by one of the professionals, but after singing an example of what he wanted, the others suggested using O'Donnell's own rendition instead. The theme premiered at the 1999 Macworld Conference & Expo. The remaining themes were written, recorded, and produced throughout 2001. The music was written with a variety of equipment, including "keyboards, synths,