I mentioned the upcoming Leonard Bernstein biopic earlier. Whilst his Broadway musical, West Side Story, was quickly turned into a film, I don’t really think of him as a movie composer.
Here are a couple of articles about composing music for the movies.
How the iconic music of 2001: A Space Odyssey came to be
When he was finally cutting the film, he started laying in this music that he’d been amassing during post and even during production. He would watch the rushes and listen to music. In fact, one of the key catalysts was, when the MGM [head] brass flew in from LA and from New York, Tony Frewin [Kubrick’s assistant on the film], who was 19 years old, the week before the MGM brass flew in, Kubrick said, “Tony, get petty cash. Get this much money and go buy all the classical music you can find downtown.”
Ryuichi Sakamoto: Coda is a reflection on how the composer hears the world
This sort of spontaneous fluidity is what has driven most of the composer’s work throughout his decades-long career. In the film, we see his restless creative energy at work, as he edits and adds to tracks while sitting on an exercise ball in his home studio. He improvises on a track playing in the background by running a violin bow across a hi-hat cymbal to unnerving effect. He listens to his environment with a playful curiosity, endlessly experimenting with whatever he can find.