Destiny Original Soundtrack
From Destinypedia, the Destiny wiki
The Destiny Original Soundtrack is the official soundtrack for the game, composed and directed by Bungie's own music composer Martin O'Donnell and co-written by Michael Salvatori, with contributions and input from famed Beatle's member Paul McCartney. The soundtrack contains 44 instrumental compositions from the game.
The soundtrack marked O'Donnell's final work for Bungie, after years of composing for the Halo franchise, as well as several games before that, as he was terminated by Bungie's board of directors without cause on April 11, 2014 . This caused concern as to whether this would affect the game; however, Pete Parsons (current Chief Operating Officer of Bungie) stated that O'Donnell's work on the game had been completed before his dismissal and would appear in the final product.
Early in Destiny's development, O'Donnell was contacted by Pete Parsons, and was asked to begin writing music for the game. At the time, Destiny was still in its infancy, as it lacked any gameplay material for O'Donnell to score music to, so instead, O'Donnell began creating music based solely on the games ideas, stories, and artwork. By February 17, 2013, over 50 minutes of the soundtrack had already been recorded with a 106-piece orchestra at Abbey Road Studios in London. O'Donnell gave the early pieces of music to Bungie in hopes that they would foster inspiration within the development team.
Unlike the Halo series, where pieces of music were only 2–3 minutes long, Martin has stated that the soundtrack for Destiny has no time restrictions, with the pieces clocking in "as long as they need to be". O'Donnell collaborated with Paul McCartney on the soundtrack for the better part of two years, as they traded ideas, melody samples, and themes back and forth.