When Oakland-based sax player Scott "Pinkmountain" Rosenberg assembled a quintet of his favorite musicians in 2006 under the name Pink Mountain—not to be confused with the Black Mountain offshoot Pink Mountaintops—they made messy, skronky, heavy experimental prog that's weirder than any music its members make outside of the band. The new, second, self-titled album is the result of studio improvisation and experimentation, with edited and overdubbed takes comprising a patchwork of sonic assault that eschews convention without shedding its essential musicality.

"The way we work, it's a crapshoot," says keyboardist Sam Coomes, also of Portland's Quasi. "You never know if it's going to be great or a disaster. At a certain point, I started thinking, 'Shit, this is pretty awesome—how the hell did this happen?' None of our other projects do music much like Pink Mountain, so we tend to surprise ourselves pretty frequently."

John Shiurba's guitar and Coomes' vocals make "Eternal Halflife" almost sound like a mellower moment from Built to Spill, were it not for Gino Robair's seasick, time-shifting drumbeat. Meanwhile, the throbbing low end of "Ditch Witch" could haunt the evilest-sounding metal track, and the ascending riff of "Foreign Rising" goes from ominous to hopeful with its repetition. Rosenberg's reeds, augmented by Kyle Bruckmann's oboe, inject a familiar King Crimson element to the progressive maelstrom, and Coomes allows his voice to sound truly unhinged—his liberated screams sound less angry than his more conventional vocals with Quasi.

Due to the band members' other projects, a Pink Mountain gig is a rare thing, but they're unraveling the new record for a small clutch of live shows. The members of the band occasionally sound like they're all playing different songs, but instead of chaos, Pink Mountain achieves a haphazard glory, a fleeting transcendence that is music stripped of any theme or emotion—but pure in its physicality.

"I often think about music as a sort of blueprint for life in a larger sense," says Coomes, "and Pink Mountain really comes close to a model of how I would like the larger world to be—lots of freedom, spontaneity, and individual expression, but with a collective sense of purpose."