In the three years since “Oh Me Oh My …,” Devendra Banhart’s startlingly strange and enchanting first album, his brand of outsider folk (alternately called new folk and freak folk) has gained many fans and musical adherents. In fact, it has become something of a movement. Along with a misfit community that includes – but is by no means limited to – Joanna Newsom, Antony, Iron & Wine, Coco Rosie, and Vetiver, Banhart has recreated the Haight-Ashbury spirit, if not its social impact.

Like those that preceded it, this instance of folk revival has a very selective take on the past. It favors the oddball, the outcast, and the misunderstood – what Greil Marcus called “the old, weird America”- over the activist folk tradition. Banhart says as much on a new song: “I realize it ain’t wise to idealize / or put your life in the hands of any struggle.”

The movement even has as its own matriarch in Vashti Bunyan, the marginal 1960s folk singer who released the pastoral – and at the time, overlooked – album “Just Another Diamond Day.” Thanks in part to lavish praise and support from Devendra and company, she is now enjoying a second act more fruitful than her first. To further spread their aesthetic, Devendra recently founded a label with Vetiver’s Andy Cabic, called Gnomonsong, that will release the music of like-minded musicians past and present.

As Ken Kesey to this band of Merry Pranksters, it is tempting to look to Devendra’s ever-evolving sound for clues about where the movement is headed (admittedly a risky proposition with a group this committed to idiosyncrasy and unpredictability). Thus far in his young career, Devendra has charted a course away from the sonic experimentation and folkloric chaos of his first work, which was populated by animistic teeth, snails, thumbs, and hands. “Cripple Crow” (XL), his fourth album, is the first that won’t baffle and unsettle the average Starbucks patrons – and may even please them.

A gentle mood is established on the first track, “Now That I Know.” Devendra sings in hushed tones over a backdrop of simple finger-picking and lonesome cello. It’s earnest, fragile, and remorseful – not unlike something off Dylan’s “Blood on the Tracks.”

This being Devendra, however, the mood is quickly complicated. Several numbers are performed in Spanish, reflecting Banhart’s Latin American roots. And with its sitar, chimes, and bongos, “Lazy Butterfly” conjures a Far East opium den. “Hey Mama Wolf,” meanwhile, becomes a kind of Indian prayer, with its spooky, chanted chorus of “hey, hey, mama wolf.”

As in the past, there are a few jokey songs thrown in. “Chinese Children” and “Long Haired Child” are amusing plays on words that continue Banhart’s thematic obsession with children. But the song that offers the most insight into his outlook and direction is “I Feel Just Like a Child,” the first single (in as much as albums like this have singles).

It is Devendra’s statement of independence from the adult world and its rational ways. “Some people try and treat me like a man / well I guess they just don’t understand / … they think I know sh-,but that’s just it, I’m a child,” he sings. He’s declaring himself a creature of innocence and whim – promising nothing but unpredictability.

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Icelandic space-rockers Sigur Ros have built a sizable international following – and no doubt helped to drum up tourism for their island country – with soaring musical evocations of the extreme local landscape. Their latest, “Takk …” (“thanks” in Icelandic), covers much the same territory.

Jonsi Birgisson is still the loveliest alien castrato you’ve ever heard; the songs beg for a laser-Zeppelin treatment at the local planetarium; and the cacophonous highs – which feature Jonsi sawing away at his guitar with a bow – still sound like old Norse gods thundering their disapproval (though the gods are perhaps a little less angry here than in the past).

The only real difference is the clicking, electronic-pastoral quality that pervades much of “Takk …” – a sound more reminiscent of the countrymen (and women) in the band Mum than Sigur Ros’s past work. In particular, “Glosoli,” the standout first single, goes for the tinkling instrumentation that the band used in their improvised accompaniment to Merce Cunningham’s “Split Sides,” performed at BAM in 2003.

The album is as good as its predecessors except in one important respect: By now, the sound has become familiar. For a group as unconventional as Sigur Ros, this (perhaps unfairly) amounts to something of a failure.

Devendra Banhart and Hairy Fairy play the Bowery Ballroom on September 14 (6 Delancey Street, at Bowery, 212-533-2111). Sigur Ros plays the Beacon Theater tonight (2124 Broadway, at 74th Street, 212-307-7171).