There’s no film quite like Birdman, Alejandro González Iñárritu’s dark comedy about a fading former star of superhero movies (Michael Keaton) battling personal demons while mounting a Broadway comeback. One reason for Birdman‘s distinctive flavor is its intense, intricate, highly original solo drum score, composed and performed by Antonio Sanchez-a bandleader and a drummer for groups led by Pat Metheny, Gary Burton and others.

Sanchez and Iñárritu first met in 2002, when the filmmaker approached the drummer backstage after a Metheny gig in Los Angeles. Sanchez was already quite familiar with Iñárritu, not only from his award-winning films, but also from his work on the popular Mexican radio station WFM, where Iñárritu had served as on-air host and station director. “The first time I ever heard Pat Metheny actually was on their night show,” says Sanchez, 43. “I was a big fan, just because they played really hip music.”

Though Sanchez comes from a family deeply rooted in cinema (his mother Suzanna is a noted Mexican film critic, his grandfather the legendary actor Ignacio López Tarso), Birdman was the drummer’s first compositional work for film. “I was excited and terrified at the same time,” says Sanchez. “There were no references for me, like, ‘Oh, I’m gonna check out this movie that only has drums that I can get ideas from.’ … Then I thought, [Iñárritu] knows what he’s doing, so we’re gonna be able to pull it off.”

Sanchez’s first pass at the score took a more conventional approach than the wildly improvisational final product. “I pay a lot of attention to film scores, and it’s common knowledge that you have themes. … So I said, maybe I’ll write different rhythmic themes for the characters, so every time you see Michael Keaton walk onstage, you hear this beat that kind of identifies him. I did a few demos and sent them to Alejandro, and he wrote me back and said, ‘This is exactly the opposite of what I’m looking for.'” When the director brought the Birdman production to New York, he and Sanchez spent several days in the studio laying down demos and rhythmic concepts. As none of the finished film was available for Sanchez to view, Iñárritu would sit at the foot of the drummer’s kit while he improvised, directing him with hand gestures to cue emotional reversals and narrative twists.

These tracks had a different sound than the final score, recorded in Los Angeles after principal photography wrapped. (The onscreen drummer seen briefly in Birdman is Nate Smith, a friend of Sanchez whom the drummer recommended to Iñárritu when tour obligations prevented him from appearing in the scenes himself.) “One of the things Alejandro didn’t particularly like about the demos was the sound itself. Since the film happens in the bowels of this old Broadway theater, he wanted something that sounded rusty and dirty and old and beat-up, so I prepared the drums in a way that I would get more of that vibe. … I had the snare drum sounding really loose with a lot of ring to it, and then I stacked up a bunch of different types of cymbals so they would sound really dry, almost like they were broken. That worked a lot better for the purpose of the film.”

Though Sanchez was nominated for Golden Globe and BAFTA Awards for his Birdman score, as well as winning numerous critics’ prizes and the Hollywood Music in Media Award, the drummer’s work was deemed ineligible for Academy Award consideration; the Academy claims that the film’s soundtrack, which also features excerpts of works by Mahler and Tchaikovsky, violates their rules against “scores diluted by the use of tracked themes or other pre-existing music, diminished in impact by the predominant use of songs, or assembled from the music of more than one composer.” In a statement quoted in Variety, Sanchez expressed his disappointment with the decision, which was upheld on appeal, “even after [the Academy received] a detailed cue sheet, a letter from the president of music at Fox Studios and a description of the [scoring] process from both Alejandro and myself. … Some of the finest composers are members of the Academy, and I’m saddened my score didn’t resonate with the decision makers.”

Nevertheless, Sanchez is applying the lessons of his Birdman experience to an upcoming album with his band Migration, due out this year. The recording, featuring saxophonist Seamus Blake, pianist John Escreet and bassist Matt Brewer, will showcase an hour-long Sanchez composition, The Meridian Suite.

“From watching Alejandro at work, I wanted to write something where I didn’t have to worry about how long it was,” Sanchez says. “Just kind of be like a movie: This scene needs to be this long, then it needs to be this long. It’s the first time I’ve written something like that. Instead of being short stories, it’s like a novel, or a movie.”