If they’re good, music documentaries can serve as a time machine — an immersive experience that transports the viewer back to the magic of another era, where the soundtrack envelops you, and an artist who has left this mortal coil returns for 90 minutes or so to validate their superstar status — a mic drop straight from the heavens. If the films are very good, they leave even hardcore fans learning a thing or two about their beloved icons. And if the films are very, very good, they completely upend public perception and, by extension, rewrite an artist’s legacy in a meaningful way.