It's only fitting that a documentary about the mid-1990s rise of the British band Oasis should contain every cliché from the rock 'n' roll handbook. There is the low birth, the abusive-then-absent father, the doting mother, the humble beginnings, the destiny narrative, the power struggles, and, above all, the colossal arrogance of the two brothers, Noel and Liam Gallagher, whose rivalry and partnership define the group.

Oasis arrived like a turkey, pre-brined in the "saviors of rock 'n' roll" mythos that led them to unprecedented success in the UK and Europe. Since the Gallaghers were fond of proclaiming that Oasis was the greatest band in the world—"Fact!"—being famous for being famous alienated them from as many people as it endeared them to, but they had a narrative and they stuck with it, much to the consternation of the '90s indie mafia. Oasis were the opposite of Radiohead in every particular, which made them all the more popular with people who felt condescended to by art rock.

The documentary is plainly authorized, executive produced by the two brothers, and entirely free of complicating details (e.g., the 13 years that followed the triumphant moment where the movie ends). In the age of the doc-as-band-primer, Supersonic does a pretty good job of showing the handful of things Oasis did best: (1) write anthems, (2) do funny interviews, (3) have good hair. Those three things are hard, and worthwhile. Having full access to the band archives, it also shows just how spectacularly massive Oasis was in mid-'90s England.

How big? Two sold-out shows in front of 250,000 people. Roughly 25 million albums sold. Bigger than any rock band is ever likely to be again, anywhere. More to the point, though, their success was cultural—even now, if you go into a pub, anywhere in England, and start singing any Oasis song (not even a big hit, either), chances are the whole place will be singing along to every word before you get to the middle of the verse. Or you'll get pummeled. But either way, you'll learn something about the British character.

The problem with the film's authorized-ness, though, is that after the band's imperial moment (which was indeed a thing to see, even if you didn't like their music or attitude), the cracks really began to show. You can see why Noel and Liam—who are still not on speaking terms, having split violently in 2009—wouldn't want to mention the Blur rivalry (literally, not one word!), or Be Here Now, or any of the many public fiascoes that followed the triumphs of (What's the Story) Morning Glory?. But as the movie goes on and on, from fabulous success to fabulous success, it's a little like when you meet someone who is still a belligerent Oasis fan all these years later: You wonder why any filmmaker worth a damn would have wanted to put together such a hagiography when a really interesting documentary was so tantalizingly close.

The fact that the Gallaghers don't let their actual story get in the way of a good myth is the biggest rock cliché of all.