“Ma nishtana halaila hazeh?” asked Marty Crandall, keyboardist of The Shins, at the start of the band’s Sunday night show. Not getting an answer from the packed Webster Hall crowd, he supplied one himself: This night was different from all other nights “’cause we came to rock!”

There are many reasons to love The Shins, the indie darlings from Albuquerque; rock-god theatrics is not one of them. The band has released two full-length albums on Sub Pop, both gleaming with lo-fi gems. “It’ll change your life,” Natalie Portman said of their music in “Garden State” – the praise that launched 650,000 discs – and she may be right. In spots they sound like Modest Mouse or countless other indie bands, but when singer-songwriter guitarist James Mercer is at his most inspired, he channels Brian Wilson. The ethereal melodies and high harmonies sound unlike anyone recording today. Listening to “Weird Divide” or “New Slang,” I remember sitting on the beach, playing guitar by the fire, watching the sun set over the Pacific. Which is strange, because I’ve never sat on the beach playing guitar by the fire watching the sun set over the Pacific.

The prospect of a three-night gig at Webster Hall raised some spiky questions. How would that fragile beauty translate to the stage, if at all? The band mostly ducked the issue. The really effervescent numbers such as “The Past and the Pending” and “Those to Come,” didn’t make the set list. From the propulsive opening number “Caring Is Creepy,” to the thrilling encore “So Says I,” the emphasis was on the up-tempo, high-energy, guitar-driven end of the catalog.

Crandall was right: The band did come to rock. With Jesse Sandoval pounding out drums, Dave Hernandez on bass, and Crandall sometimes joining Mercer on guitar, the Shins proved they can become a reasonably convincing rock quartet when they want to. Played live, the propulsive “Know Your Onion” was musical caffeine. But other songs fall flat when performed this way. “One by One All Day,” a standout track from their debut LP “Oh, Inverted World!” lost its flavor onstage. A new song, leaning heavily on the guitars, also didn’t inspire much affection.

Even in these middling songs, there’s no confusing the Shins with anybody else. For that distinction, the band can thank the larynx of James Mercer. He doesn’t look all that happy to be up there in front of the crowd. Stashed away at stage left, he looks like a grad student pressed into service as a vocalist-guitarist. (Center stage belonged to Crandall, the band’s rampaging extrovert, who bantered with the crowd, kept the beat by marching in place, and distributed the pink flowers that someone threw onstage so that everyone wore one behind an ear, except Crandall, who wore two. Jack Black will play him in the movie version of their lives.)

Stage blocking aside, it’s Mercer who gives the band its identity. Like Thom Yorke, he has a high, urgent tenor that makes even very abstract lyrics (to put it gently) and a conventional guitar line sound dynamic. The happy discovery of the show is that Mercer’s voice is even more gorgeous than their records would lead you to believe. On the album version of “Saint Simon,” Mercer sounds indifferent, like a young Robert Smith. Onstage, forced to compete with crashing instrumentation all around him, he comes alive, and so does the song. Sandoval drives the beat, Crandall supplies a high “la-la-la” refrain, and the crowd vibrates along. It’s one of the highlights of the show.

Otherwise the highlights lay where you’d expect to find them, in the weightless atmospherics of songs like “New Slang.” The wizards of Webster Hall waited until that number, an hour into the 75-minute set, to activate a starry-night backdrop behind the band. “Oooh,” cooed the crowd, as more than a dozen cameraphones flared to life. One quiet number, “Young Pilgrims,” proved more satisfying live than on its album, “Chutes Too Narrow.” Played as a simple duet, Mercer on acoustic and Hernandez on electric, the song conveyed more sad loveliness than you’d think it possessed. In a few albums’ time, when their library of songs like this one is sufficiently large, it’s easy to imagine Mercer and the band playing hushed, Magnetic Fields-style shows at places like Zankel Hall. This is, after all, the great and singular appeal of the Shins. Many can rock, but who else can shimmer?

***

Also, some can swing. The opening act, the Brunettes, are making their first trip from their native New Zealand, and they have brought the brass section with them. The seven person lineup included two saxophones, trumpet, clarinet, xylophone, and cello – imagine attractive Kiwis turned loose in a music shop, and you’ve got the idea. In the manner of Polyphonic Spree (with a rhythmic nod to Talking Heads and a vocal one to Bjork), the band thrives when it gets a lift from the brass, and doesn’t much captivate without it. For the closing number, a weird little tribute to the Olsen twins, the band donned masks of Michelle Tanner, the twins’ character from “Full House” – a really unnerving spectacle. The night was also different from all other nights because of the quality of my nightmares.