IN THEIR HOME country of New Zealand, the Mint Chicks were legitimately famous. The charged pop-punk group had fans, major label support, world tours, and music videos complete with special effects. Frontman Kody Nielson was a provocative live wire, while his brother Ruban played guitar, and in 2007 the Mint Chicks moved to Portland. Approaching nearly a decade together, nerves were rubbing raw. In 2010, Kody reportedly attacked Ruban onstage.

The brothers went their separate ways. Kody returned to New Zealand where, according to Ruban, he dates a pop star. Ruban decided to stick it out. He remains in Portland with his wife, who earlier this year gave birth to their second child.

Freed from the Mint Chicks' defined aesthetic, Ruban became inspired. Recording at home, he wove together catchy '70s funk, '80s-era hiphop breakbeats, psychedelic harmonies, and shimmering guitar. With flickers of detachment and dusty grime, the resulting songs feel somewhat like a rejection of the Mink Chicks' straightforward, maximized, sturdy pop. Conversely, these clattering hiphop breaks evoke a tumbling scratch, as if always threatening to collapse to the floor in a heap of pieces. But even as he stretches out his sound, Ruban's hooks wiggle through, as even his slinky, arid dissonance belies an underlying sweetness. Unlike his brother, Ruban is not a confrontational frontman. Even when his music gets heavy and loud, Nielson's laidback touch remains soothing. If there is anger or dissonance, it emerges from his guitar, but even then, keys change and chords resolve. He called this project Unknown Mortal Orchestra and released the songs online anonymously.

Without any promotion, the songs quickly began gathering steam online. A boutique label in the UK released a 7-inch single, and soon there were requests to tour. Nielson recruited bassist Jake Portrait—an engineer who had previously worked with the Mint Chicks—who then brought along the 19-year-old Julien Ehrich, a family friend, on drums. Together, UMO resembles a classic power trio. All three are consummate players.

For Ehrich, it's been quite a baptism. He joined the band right out of high school. Were it not for UMO, he'd be starting college. Instead he's touring the country in a buzzed-about band, playing in clubs he's otherwise not allowed to enter. For Portrait and especially Nielson, this is well-worn territory. They know what to expect, yet they don't seem to loathe it. On the contrary, Nielson is grateful for the opportunity to support his family with his art, and to an outsider, UMO looks like they're still on their honeymoon.

The band quickly signed to the Fat Possum label and their first show soon followed, opening for the Smith Westerns (another buzzed-about band on the label) at the Doug Fir in February. UMO toured to New York and then immediately flew back to Portland to start another run supporting Starfucker to SXSW. After that there was another. And another. Earlier this month they debuted in Eur-ope. The band's self-titled full-length—a remastered collection of the original home recording with a few additions—came out in June.

Things have moved fast for UMO; there have been surreal shows, stolen guitars, embarrassing interviews, and wild, forgotten nights. But over and over again in conversation, the band conveys how much good fortune they've experienced in such a short amount of time. Easy come, easy go—sometimes it really works.