When Dirty Projectors appeared on Late Night With Jimmy Fallon a month ago, Roots drummer and Late Night bandleader Ahmir “?uestlove” Thompson was smitten. “I will follow y’all to the end of the earth,” Thompson said at the end of a rehearsal video he posted to Twitter.

Judging by the critical response Dirty Projectors has received this year, ?uest isn’t the only one. The Brooklyn-based sextet’s Bitte Orca, released in June but recorded largely in the summer of 2008 at Portland’s Union Hall, is a major leap forward for the band and its one consistent member, Dave Longstreth. It’s a record of intricate, layered arrangements for guitar and voice that takes more cues from Malian guitarist Ali Farka Touré than buzz bands like Animal Collective.

“We had toured so much for [2007 album] Rise Above, and when you’re touring like that, New York doesn’t always feel like the most restful kind of home to come back to,” Longstreth says. “I think we were all excited to record it out West.”

Longstreth had lived in Portland in the past, and it was during an early immersion in the local experimental music scene that Longstreth met Adam Forkner (a.k.a. White Rainbow), Adrian Orange and Curtis Knapp (founder of Marriage Records)—figures important to the development of his first material. Dirty Projectors’ earliest records—including 2003’s Morning Better Last!, released on local label States Rights Records, and the Marriage Records EP New Attitude—were off-kilter sketches that jumped from distinct genres (one-man blues, spare acoustic folk, neo-classical pieces) and never found a unified sound. In those days, Longstreth saw Dirty Projectors as an amorphous unit, and it wasn’t until touring on Rise Above—a weird reimagining of Black Flag’s Damaged that gained Dirty Projectors considerable notice—that he brought in a unified group (guitarist-vocalist Amber Coffman, keyboardist-vocalist Angel Deradoorian, vocalist Haley Dekle, drummer Brian Mcomber and bassist Nat Baldwin) and began writing songs that combined all his interests.

“It was never really a priority for me to have a consistent band, because I figured I’d write a batch of songs and they’d all have a specific skeleton,” Longstreth says. “But it’s been super awesome to solidify the band and start to do it the opposite way: Write with everybody in mind, write a part that Brian would sound amazing on or a melody for Amber.”

Indeed, Bitte Orca’s highlights showcase members of Longstreth’s band, especially vocalists Coffman and Deradoorian. “Stillness is the Move” is a groovy RB number: a slinky, rhythm-based platform for Coffman to open up her gorgeous falsetto and coo all over Longstreth’s loping fret work. “Two Doves,” on the other hand, is completely percussionless, with just Longstreth’s spare finger-picking and a string quartet backing Deradoorian as she sings of a love unfulfilled. The women’s voices are similar at first, but it’s the slight contrast between the two—especially set against Longstreth’s unrestrained yelp—that anchors the strong middle section of the record and gives it an experimental edge.

Things only get stranger on “When the World Comes to an End,” a sparse, pretty song where the three female singers showcase an impressive vocal technique called “hocketing.” Known mostly to musicologists as a staple in medieval music, it’s a compositional tool largely foreign to the rock world. But due to the strength of their pipes, it sounds natural when Coffman, Deradoorian and Dekle engage in a vocal game of pingpong.

Longstreth’s deftness with vocal arrangements is one of the things that attracted Icelandic pop icon Björk to collaborate with the band. Talking about Björk leads Longstreth to geek out (“I still can’t believe she was in my apartment!”) and offer up a description of the collaboration that speaks as much to the Projectors’ music as to Björk’s: “It was like watching water find its way down a hillside,” he says. “It’s trickling and then all of a sudden it’s boring through the silt, making these caverns, yet somehow knowing where it’s going the whole time.”