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.

[1][2] O'Donnell stated that he approached the project "with fear and trepidation"[1] and that his main influences were music he liked—"a little Samuel Barber meets Giorgio Moroder".

[1] 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".

[1][4] The soundtrack features a wide range of sounds O'Donnell described as "Gregorian chant, string orchestra, percussion and just a bit of a 'Qawwali voice'".

[1] Working closely with level designers, O'Donnell divided the music into "chunks", which could be played back dynamically by the audio engine depending on the player's actions.

IGN praised the soundtrack for its wide use of instruments: "Where other videogame scores tend to miss their mark when combining electronic and organic elements, O'Donnell and Salvatori seem to have found a rather stable balance between the two divergent sounds."

[8] Reviewing for Monsters At Play, Michael Johnson called the soundtrack "66 minutes of orchestral goodness," citing the wide range of music covered as a strong point.