Before he became Bon Iver, folk singer Justin Vernon started a band called DeYarmond Edison in Eau Claire, Wis., with brothers Brad and Phil Cook and drummer Joe Westerlund. When, in 2007, Brooklyn freak-folk troubadours Akron/Family took their bombastic statement Love Is Simple on the road, they made their quartet a septet with the addition of Megafaun, a trio Vernon’s backing band started after moving to North Carolina. In September, the group will join forces with avant big band Fight the Big Bull for a recording project commissioned by Duke University. Because of the group’s long history of collaboration, it can be easy to miss what Megafaun have accomplished on their own terms—like, say, last year’s Gather, Form & Fly, which pulled an 8.1 on Pitchfork and four stars from Rolling Stone.

Since the band had scraped most of the “freak” off of their banjo-driven folk for Gather . . . it was a surprise to watch them open their Friday-night set with some swelling electric psych-folk, recalling Neil Young as much as Akron/Family. As the show progressed, it became clear why Megafaun have become such in-demand sidemen—the band’s range, versatility and musicianship rival anything in the greater Fleet Foxes/Vetiver folk-sphere. The Cook brothers casually swapped electric and acoustic guitars, banjo, bass and wisecracks, while Westerlund defied almost every drummer stereotype by singing crisp harmonies, taking lead vocals, and commanding a full table of electronic effects.

As they moved through older tunes, as well as stuff off of their new “mini-album” Heretofore, two bands seemed to emerge. Electric, the group relied on gentle drones, patient post-rock buildups, and song structures that seemed to dissolve verses in and out of instrumental passages, not unlike the tape experiments on the Grateful Dead’s Aoxomoxoa.

Stripped-down, however, is the way this band ought to be known. Old-time picker “The Fade” and “Kaufman’s Ballad” exhibited the kind of natural three-part harmonies and sing-along hooks that caught critical attention last year, and they might have outdone themselves with their new single “Volunteers,” which arrived late in the set.

It’s hard not to use Vernon as a reference in describing the humble charm of Megafaun’s acoustic material, but more than a Bon Iver spinoff, and with versatility that plenty of other acts are drawing on, the band seem primed to finally assert themselves.