noconcessionsTwenty years ago, more than two million Brits tried to buy tickets to see Oasis at Knebworth, and 250,000 concertgoers experienced the band at its height over two evenings. “Two nights sold out,” comments Noel Gallagher, as footage from aerial cameras captures the enormous audience. No stranger to hyperbole, he adds, “We could’ve sold out seven. We might still be playing!”

Tomorrow night only, experience peak Oasis on the big screen in Supersonic, which begins and ends at Knebworth. The documentary spends much of its two hours in reduced circumstances, however, as younger brother Liam founds the band with mates named “Guigs” and “Bonehead” in Manchester, roadie Noel eventually joins with some songs he’s written, and Oasis zooms to the top of the pops when Creation Records co-owner Alan McGee spots them at a gig in Glasgow in 1993. Or, rather, zigzags. Warring egos and lots of drugs interfered with the recording and promotion of their 1994 album Definitely Maybe, which hit No. 1 in England, and landed them their first American booking, at L.A.’s famed Whisky a Go Go. Mistaking crystal meth for cocaine the Gallaghers (who had already been kicked out of the Netherlands for brawling with a ferryful of football fans) went on an epic bender before showtime, and played a shambolic gig, with Noel on one setlist and Liam on another. Liam, annoyed, threw a tambourine at his sibling, who retaliated by flying off to San Francisco and quitting the band. (This was a reversal of the usual pattern, which saw Liam storming offstage so much that Noel took up singing to cover his absences.) The entire fracas, and more besides, are replayed in detail. At one point, Noel recalls that it “wasn’t quite fair” when Liam hit him over the head with a cricket bat during the recording of their smash-hit followup, (What’s the Story) Morning Glory? (1995)–or maybe it was Liam complaining about Noel. Neck deep in “fucks” and “cunts” by this time, I lost track of who was battling whom.

Produced by Asif Kapadia (of the Oscar-winning documentary Amy) and directed by Mat Whitecross (of the Ian Dury biopic Sex & Drugs & Rock & Roll, starring Andy Serkis), Supersonic is actually rather gentlemanly. The band’s infamous feud with Blur and other tabloid travesties are avoided, to focus on the music. Blocking out everything else Oasis could lay down tracks like the epic “Champagne Supernova” with lightning speed, and their own hype wasn’t unfounded. Their secret may have been their patient, indulgent mum, Peggy (a luv, as they say across the pond, who raised her sons on their own after their abusive father took off), and their dedication to rock and roll beyond the lifestyle perks of “birds,” booze, and drugs. “We were the biggest band in the country but we didn’t give a fuck,” Noel said after Oasis won a bunch of Brit Awards in 1996. But beneath the swagger, they did. When their bassist briefly quit due to “nervous exhaustion,” Liam was staggered. “Nervous fucking exhaustion? That’s what rock and roll is!”

While Supersonic evades some aspects of Oasis’ glory days, the film, narrated by the brothers over reams of deftly assembled and seamlessly edited footage, is raucously funny in a way that most music documentaries aren’t. True to one of their hits, they don’t look back in anger, seven years after the band finally folded, and have kind words for one another. Their greatest rapport, they say, was with their audiences, and reveling in “having the crowd sing our songs back to us.” Including one middle-aged film critic, who happily hummed along with them in a Manhattan screening room.