Nicholas Britell is one of the more progressive voices in modern movies, a composer as capable of tapping into hip-hop and electronic music as the familiar powers of a 100-piece orchestra. As a through-line listen, his soundtrack for Don’t Look Up is all over the place: bustling big band (“It’s a Strange Glorious World,” “Main Title Theme”), twinkly synths (“The Call”), and fake institutional music to match director Adam McKay’s mordant, sobering sense of humor (“BASH Corporate Ident,” ”On Hold"). But in Britell’s eclecticism is a new model of what a soundtrack can be: Feet in the past, eyes on the moment.