In the credits, Blackhat’s (2015) score is attributed to Harry Gregson-Williams, known for his work on Shrek (2001), The Chronicles of Narnia (2005), and Kingdom of Heaven (2005). Despite that, he has been quoted saying that very little of his score actually made it into the film. From an interview with Variety:

“After attending the premiere, Gregson-Williams posted on Facebook that “the ‘score’ for ‘Blackhat’ may be credited to me but contains almost none of my compositions. … I was not the author of most of what is now in the movie.”

He added: “I therefore reluctantly join the long list of composers who have had their scores either sliced and diced mercilessly or ignored completely by Michael Mann. This is his film and these are his decisions, and I do respect that, but see no reason to have people mistake this score for one that I composed, or in any way approved of musically.”

While Gregson-Williams isn’t bitter about his score being cut, he’s unhappy about still being given credit for music that isn’t his. Crediting him for work he didn’t do is misleading to his fans and portfolio.

In a statement, Mann responded: “Harry’s a talented composer whose music needed editing and remixing to fit the contemporary subject and ambitions of our picture. He was one of four composers who contributed to the score, along with Atticus and Leo Ross, Ryan Amon and Mike Dean. It would have been preferable to me, too, if the delivered music could have been used as it was.”

Ryan Amon is a composer known for Elysium (2013) and Chappie (2015), and Mike Dean is a Grammy Award-winning hip hop producer. Atticus Ross is the Academy Award-winning composer (alongside Trent Reznor) for his work on The Social Network (2010), and the pair took home a Grammy for their work on The Girl with the Dragon Tattoo (2011). For Blackhat, he composed with his brother, Leo Ross. Together, these composers, along with Gregson-Williams, all contributed to the Blackhat score after editing was performed by Mann’s team. The usage of multiple composers for a single film is standard procedure for Mann.

Variety continued:

“Composer Elliot Goldenthal, who initially scored for Mann on “Heat (1995),” said after working with him a second time on “Public Enemies (2009)”: “Michael has a propensity to change his mind the whole time. For some people it can be very frustrating. You think you’ve accomplished something, but you never know. It’s Kafkaesque.”

Adds another composer who has collaborated with Mann, and who asked for anonymity: “He gets all this music from loads of people and then puts it together in a way that he likes. He’s not a musician, and sometimes it’s led to something great, and sometimes it hasn’t.”