In the 1980s, music and film collided for cross-promotional blockbusters both transcendent (Purple Rain) and transcendently cheesy (Footloose). In the ‘90s, soundtracks continued to sell in the millions, capturing cultural moments like the Seattle grunge of Singles or the Britpop and electronica of Trainspotting. Auteurs like Quentin Tarantino and Wes Anderson reached deep into their record collections to set the mood while movies like Above the Rim and Menace II Society pioneered the concept of soundtracks as hip-hop mixtapes. A great soundtrack can propel an unsuccessful single, like Seal’s “Kiss From A Rose,” to the top of the charts, or revive a decades-old hit, like Queen’s “Bohemian Rhapsody.” It can also push a cult singer-songwriter like Elliott Smith or Aimee Mann to an Oscar perf...