 Favreau had a clear vision of heavy metal music and guitars for the project, saying that Tony Stark was more of a rock star than a traditional superhero.Djawadi subsequently composed most of the film's score on guitar, before arranging it for orchestra.Djawadi had help with arrangements and additional cues from Hans Zimmer and Remote Control Productions, and Rage Against the Machine guitarist Tom Morello, who makes a cameo appearance in the film, contributed guitar performances to the score.