A documentary by Sacha Gervasi. Unrated.

There’s something sad about old rockers who keep on doing the same thing well into their Metamucil years. But when we’re laughing at Mick Jagger and Steven Tyler, it’s only because they’ve kept us so aware of their geriatric prancing. But what about the guys still at it who we’ve never heard of?

My own knowledge of Canadian metal bands of the 1980s is sketchy, and I didn’t know anything about Anvil, a Toronto quartet whose sledgehammer riffs and 666-minded lyrics influenced the coming generation of metal bands. That’s what guys like Slash, Motí¶rhead’s Lemmy, and Metallica’s Lars Ulrich tell us in this lovingly made documentary, and why would they lie about a thing like that?

For whatever reason, ahem, these Canucks didn’t make it to the playoffs, and after some background, the film heads to wintry Toronto to catch up with the founding, now 50ish duo of singer-guitarist Steve “Lips” Kudlow and drummer Robb Reiner. More than the last guy’s name recalls This Is Spinal Tap, the trendsetting mockumentary that could have been about Anvil if they were smart enough to have been born British, and fictional.

Even the title Anvil! The Story of Anvil has a Nigel Tufnel–esque ring to it, and our guys—nice Jewish boys from the ’burbs who never learned any moneymaking skills, plus two other directionless dudes—do end up visiting Stonehenge.

This terrific doc’s writer-director, L.A.–based Sacha Gervasi, roadied for the band as a teen and since wrote The Terminal for Steven Spielberg. He has a keen eye for unintended comedy and the big-screen drama inherent in lovable, foul-mouthed lunkheads who have stuck together, sometimes to the exclusion of their generally supportive wives and families, in order to stay hell-bent for leather—and Depends.