IF YOU'VE SEEN one music documentary, you've seen them all: The huddled musicians lost in concentration behind some dimly lit recording studio soundboard, the "real" backstage personas (usually relatable, since rock stars are just like you), and the occasional bouts of inter-band horn locking, since they are, after all, artists struggling in their craft.

Mistaken for Strangers has none of these things.

At their very precise (and admittedly drab) core, the National's dual pairings of siblings—guitarists Aaron and Bryce Dessner, and Scott and Bryan Devendorf (bass and drums, respectively)—along with dreamboat/baritone singer Matt Berninger, are domestic rock 'n' roll's melancholy saviors. But they're hardly exciting to gaze upon on the big screen: Painstakingly fastidious musicians do not make thrilling documentary fodder, which is why the National wisely duck the spotlight of Mistaken for Strangers in favor of Tom Berninger, the film's impromptu documentarian and the loveable fuck-up brother of frontman Matt. Tom was coerced—by his mother, naturally—to join his brother's band on the road and make something of the smoldering ruins of his life.

Like a Chris Farley SNL skit come to life, the rotund Tom is a delightfully chaotic presence on the screen. The bull in the band's china shop, he attempts to juggle remedial touring band chores (delivering the guest list, not getting high with the drummer), alongside the reluctant acceptance that his brother's success is smothering him. As the overly patient Matt encourages his younger sibling to indulge in his artistic pursuits, Tom's blundering antics act as a wrecking ball, with his sights set on the unsuspecting band and crew. The footage of the Berninger brothers in disarray and the National's meticulous little world laid to ruin makes for a grand, fascinating departure from the well-trod soil of music documentaries.