Director Damien Chazelle cares deeply about music. His film “Whiplash” is about a drummer and “La La Land” is a musical. He worked with composer Justin Hurwitz, who won two Oscars for “La La Land” on all three. In this video, Hurwitz talks about working with Chazelle again on “First Man,” which involved a lot of firsts for him, including learning how to play the theremin.