Michael Giacchino, the composer of the soundtrack, started his career at Disney Interactive, and was later contracted to write the score for Call of Duty's predecessor, Medal of Honor. Due to this previous work, Activision signed him on to compose the score for Call of Duty. Comparing his work on Call of Duty and Medal of Honor, Giacchino aimed for a score that would reflect the "chaos that surrounds you in times of combat and also of the millions of prayers that must have been said in the darkest of moments." He felt that Medal of Honor lacked "the ugliness of war in its more combat action moments," which he sought to rectify in Call of Duty's soundtrack by making it more "visceral and brutal."