When actor, director, and composer Melvin Van Peebles asked Earth, Wind & Fire to perform his score for his pioneering indie film Sweet Sweetback’s Baadasssss Song, the band was one album deep, getting booed, and struggling to eat. Not only did it properly start their career, but it inspired a wave of soundtracks that helped shape ’70s R&B and funk, including Isaac Hayes’ Shaft and Curtis Mayfield’s Superfly: music that felt deeper, grittier, more soulful and uncompromising than the class before. (And that’s to say nothing of the countless hip-hop artists—such as MF DOOM, KMD, and Digable Planets—who sampled it.) Of special interest is the tense Latin soul of “Sweetback’s Theme” and the almost proto-rap delivery of “Come On Feet.” Bassist Verdine White said the band got paid $500. Or at least they would’ve if the check hadn’t bounced. Later, Van Peebles said he figured that if he barely had money to make the movie, he’d have to get some pretty good music to help sell it.