Squaring the Circle, which I just saw on Netflix, a documentary on Hipgnosis, a company primarily known for album cover art. You'll see interviews with Peter Gabriel, all surviving members of Pink Floyd, Robert Plant, Jimmy Page, Paul McCartney, Graham Gouldman, Po Powell (the surviving founder of Hipgnosis) and surely some others I can't recall off the top of my head.
Things I should have known but didn't: the cover for the Pink Floyd album Wish You Were Here, with the two men in suits shaking hands and one guy on fire, featured an actual stunt man on actual fire. They did many takes in search of the "perfect" shot until the wind shifted and caused the flames to envelop the stunt man's face, after which the stunt man announced that the shoot was complete.
Just watched this. Some dude called Noel Gallagher is also interviewed. "Why didn't you use Hipgnosis?" "Couldn't afford them!" He has a story about telling his daughter he had to go to a meeting about cover art. "What's cover art?" she asked. "What the fuck's an album cover?"
Despite the squaring the circle animation being used continually throughout the film, I'm embarrassed to admit how long it took me to realise that's what the title means.