Even though Anvil, a four-piece speed-metal circus that once toured with soon-to-be cash-cow longhairs like Whitesnake and Bon Jovi, never amounted to anything more than “the demigods of Canadian metal,” guitarist Steve “Lips” Kudlow and drummer Robb Reiner decided early on that their sole objective was “to rock forever” and at all costs. Sacha Gervasi, a British screenwriter (The Terminal) who’d roadied for Anvil as a teenager, reunites with Kudlow and Reiner for this phenomenal rockumentary, whose first half follows the band on their biggest tour in 20 years to Europe. The five-week trek turns out to be a logistical nightmare: They miss trains in Sweden, get lost in Prague, and perform in Transylvania to 174 people in a 10,000-capacity arena. But that’s nothing compared to later scenes of Anvil in the studio recording their 13th album with money Lips borrowed from his sister—their last-ditch attempt at mainstream recognition. Robb threatens to quit, Lips ends up crying into the camera, and everyone engages in emotionally weighted therapeutic discourse. Yet somehow these Headbangers Ball footnotes, with their intentionally goofy groupie anthem called “Show Me Your Tits,” end up being far more human and likable than the Mighty Ducks. (NR) CAMILLE DODERO

June 15-17, 9:20 p.m., 2009