PHOTOGRAPHS BY CASS BIRD

Dave Portner is freaking out. Better known by his cryptic sobriquet Avey Tare, he's lying flat on the floor, eyes open wide, startled by something invisible and evidently very strange in the air above. Bandmate Brian Weitz, or Geologist, is splayed out beside him, swaying his head from side to side extreeeemely sloooowly. Noah Lennox, or Panda Bear, sits like a statue nearby, completely zoned out.

We're at Dream House, an instructive place to convene with the phantasmagoric art rock outfit Animal Collective. Hidden in a walk-up loft, Dream House is an escapist refuge in lower Manhattan -- a spacious room empty except for scattered pillows and four huge stacks of speakers. A light installation gives the room an ambient purple glow, but the story is the roaring drone. Devised by the minimalist composer La Monte Young, the noise cycles through continuous loops that sound static at first but then start to change, or seem to change, with the slightest shift of the listener's perspective; it's hard to tell the difference between what you're hearing and what you're imagining -- not to mention whether you're awake or asleep.

"I actually had a couple of crazy dreams," says Portner, 29, sipping mango juice a half hour later at Tokyo Bar, a hideout down the street with oversize comic-book art on the walls and Japanese funk on the stereo. "I got close to dozing off a couple times and had these rhythmic starts. I'd wake up and be like...wow. It was insect-y at times, too -- a lot of insect sounds."

Lennox, 30, can't remember if he's been to Dream House before. It's hard to imagine forgetting an experience so bizarre and all-consuming, but anyone who calls himself Panda Bear seems just ethereal enough to rise to the task. Lennox is the most stoic and shy member in Animal Collective, but also the most mercurial. Portner is smiley and excitable by comparison, and Weitz, 29, whose beard makes him look like an actual geologist, speaks with an easygoing, earthy clarity about matters both conceptual and concrete. "I was thinking," Lennox says, comparing the Dream House din to an elusive conversation that took place on the way there, "that was a really good example of the magical sound I was talking about."

Animal Collective talk a lot about magical sound. They traffic in buzzes and moans for a livelihood, and they're more than happy to be perplexed by these noises' mystifying effects. They're perfectly at home at a place like Dream House, which -- like the weird world fashioned by Animal Collective at mesmerizing live happenings and on albums like their new Merriweather Post Pavilion -- serves as a sanctuary for sound that skews as arty and abstract, electronic yet somehow ancient, beguiling, bedeviling, soothing, scary, and serene.

When they started playing in New York City around 2000, Animal Collective weren't exactly a band. Their first CDs were paper-cased curios that showed up on the shelves of select East Village record stores, and early gigs were mysterious gatherings where the guys might preside over a one-chord jam in a theater with films of themselves rolling around in the desert. All that was known about them, before music blogs existed, was that they grew up together in Baltimore.

It wasn't much to go on. But at a time when New York was buzzing around the showy rock scene embodied by the Strokes and forthright, flashing dance-punk bands such as the Rapture, Animal Collective started to simmer as a sort of shadow phenomenon. As their name began to circulate, the band hid behind demented masks and seemed to vanish for long stretches at a time. Still, none of that stopped a wave of inquisitive whispers and rising suspicions, however hyperbolic at the start, that Animal Collective might be the best thing going.