If you’re someone who treasures the music of Led Zeppelin more than you’re interested in the legend—or the gossip, or the dirt, or whatever you want to call it—of Led Zeppelin, this movie is absolutely for you. I’m one of those people, and I ate it up.

But before we absolutely abandon the realm of gossip/dirt/legend, we should say that “Becoming Led Zeppelin” wouldn’t truck in any of that stuff in the first place because to make a documentary about Zep, you need Zep’s music, and to get Zep’s music you need Zep’s approval. So what we’ve got here is the only kind of documentary you can make about Zep and its music: an authorized one. This picture was made with the full cooperation and—to judge from the interview clips—enthusiastic participation of the group’s surviving members. The emphasis is on not just the music but the influences and the career paths that fed it. True to its title, it’s about the formation of the group, and it ends after their first U.S. tour, which saw them go from small club gigs to big concert halls as word of their incredible shows spread across the country.

You couldn’t make a hagiography of this combo even if you wanted to; their personalities are too vivid. Yes, the picture, directed by Bernard MacMahon, presents surviving members Jimmy Page, Robert Plant, and John Paul Jones as pretty nice guys—and, in addition to being pleasant, they’re all persons of keen intelligence who are able to easily articulate that intelligence at all times, and they’re game storytellers to boot. But there’s nothing in the way of visible plinth-building for them.

While Jones and Jimmy Page were long-time colleagues, veterans of the ‘60s British rock sessions scene (that’s them making a mighty noise on erstwhile folk-rocker Donovan on the psychedelic metal classic “Hurdy Gurdy Man” AND, as Jones amusingly recounts, playing on the title song of the James Bond classic “Goldfinger”), Plant and wild-man drummer John Bonham were gigging rockers who’d played together in Plant’s early ensemble Band of Joy. Page, the last man standing in the protean English group The Yardbirds trying to keep that train a-rolling, heard the guys and eventually hired them (Plant and Bonham had gone separate ways at that point) with the hope of making the combo The New Yardbirds.

The first time the quartet played, they clicked like mad, with an energy all its own. Page realized these weren’t new Yardbirds—this was something wholly other. It was madcap Who drummer Keith Moon who gave them their name, disparagingly speculating on how the group would go over. The last laugh would be Page’s as they laid down their classic first album in a mere 36 hours (spread out over a few weeks in the fall of 1968). And then followed up less than a year later with the even heavier Led Zeppelin II.  Recorded in the midst of an American tour that took them West to East, playing bigger and bigger venues as word of mouth spread.

All this is conveyed with the generous contemporary interviews interspersed with archival footage (which, of course, is the only way Bonham can appear), including glimpses of the group’s manager Peter Grant, who you can tell just by looking at him was the bad guy of the enterprise.

The movie ends with the three members listening to a tape of a rare interview with Bonham, who died in 1980 of pulmonary aspiration after a binge, talking with great affection and pride about his work with the band, and saying “I don’t need to do anything else.” The fellows are moved, and you will be too.

But the main attraction is finally the music, of which there is plenty. The opening title of another great (albeit very different) rock and roll picture, “The Last Waltz,” says, “THIS MOVIE SHOULD BE PLAYED LOUD.” Nobody needs to tell the IMAX projectionists who run this picture—both times I’ve watched were at ear-splitting volumes. Which is entirely as it should be. But you might want to consider bringing earplugs.