Since they formed in 2000, The Avett Brothers have swelled their fandom from the locals of their North Carolina roots to sprawling crowds that flood stadiums of sold-out world tours, all lured by this beloved band’s whimsical mix of folk rock, country, bluegrass, pop and punk. Among these fervent fans is film producer Judd Apatow, who teamed with RadicalMedia to bring the origin story of this heart-warming musical act to SXSW with “May It Last: A Portrait Of The Avett Brothers.”

Apatow and documentarian Michael Bonfiglio share directing credit on the documentary that that travels from the Avett Brothers’ lively stage shows to their loving homes and the studio where they recorded the album “True Sadness.” Fans of the Brothers will relish the film’s earnestness in showcasing their authenticity and easy appeal, as well as the intimate moments of this fun-loving family. However, those who aren’t die-hards might find this musical journey a bit meandering.

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“May It Last” begins with some basic background, setting up where the members of The Avett Brothers band — which includes a drummer, fiddler, keyboardist, cellist, and a standing bassist — are in their career. After a steady rise and selecting famed music producer Rick Rubin (whose worked with everyone from Johnny Cash to Kanye West), the group finally seems on the verge of their big, defining breakthrough. Then interviews with their friends, family, and managers offer some insight into older brother/lead vocalist Scott Avett and younger brother/banjo player Seth Avett, who share songwriting and guitar work. Ever the extrovert, “Scott is like a carnival, coming at you with all the rides,” while Seth is readily and repeatedly described as the sweetest man alive. Together they play melodically and blissfully. Watching the two compose songs and horse around together is pleasant. In many ways, this movie is a big hug, warm and rejoicing. It’s just not much of a movie. There’s no source of conflict, and little sense of momentum.

Now, “May It Last” is not all gleeful performances and smiling interviews. A pair of segments are dedicated to the health crisis one of the band mate’s family faced, while another briefly touches on Seth’s divorce from his first wife. These moments are touching, especially as their focus becomes how the band mates pulled together to tug each other through such trying times. But there’s no conflict that carves an arc out of this doc.

The film winds back to their rebellious youth where the Avetts favored Nirvana and the affiliated grunge wardrobe to the acoustic guitar and country influences that would come to define their signature sound. It’s a delight to trip down memory lane with the deeply bonded brothers, whose parents and siblings can’t stop grinning while discussing them. But with no drama between them, I waited for any obstacle to come their way. Instead, they happily recount how double bassist Bob Crawford first urged the reluctant two to tour. “We were self-centered hillbillies that thought the world would come to us,” laughs Seth, commending the good judgment of his friend and bosom buddy.

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Rather than wistful moans over unachieved acclaim or fame, audiences get inspiring speeches about how the Avett Brothers stayed true to themselves, even when pressured by interested labels to change to something easier to market. Do they lament they’ve never had a big single? Sure. But more than anything, they value each other and their music! It’s aspirational, and sweet as Seth, but ultimately boring. Even when they achieve the goals they briefly pondered with a half-smile, these are treated like afterthoughts, bonus cherries on top of an already superb sundae.

“May It Last” plays more like a puff piece than a concert doc, never digging to discover the hard sacrifice to this hectic touring schedule, the dirt beneath the fingernails of such work. Maybe there is no dirt for the Avetts. After all, one band member said of the brothers, “It’s almost like a Disney movie.” Fine. But even a Disney movie needs a villain, a challenge, or a quest to get the adventure going. [C+]

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