Ben Bridwell – the heroin-thin, heavily tattooed, and hirsute lead singer of Band of Horses – began Friday’s show at the Bowery Ballroom (the first of three in town over the weekend) sitting with a lap-steel slide guitar. His excitement didn’t allow him to stay seated for long, however. By the end of the first song – the measured-then-climactic “Monsters” – he was on his feet, body bent over at nearly 90 degrees, flaying the instrument in frantic, full-body sweeps.

Such unrestrained enthusiasm is typical of the Seattle-based band, which combines disarming modesty with visible joi de rock. In a room full of people happy to be there, none were happier than the band. They rapped the words to T.I. and Chamillionaire songs playing over the PA as they set up their instruments. Between songs, they offered heart-felt thanks to the guys behind the soundboards for making them sound so good and exclaimed “cheers bros, alright” as if they were the ones applauding the crowd.

Their cheerfulness and dizzy sense of good fortune is understandable given their quick success. Formed from the ashes of minor Seattle dream-pop act Carissa’s Weird, Band of Horses only released its debut, “Everything All the Time” (SubPop) in March. But after a breakout performance at this year’s South by Southwest festival (which maintains its critical band-launching role even in the era of Pitchfork and blogs) they’ve suddenly become one of the most lavishly praised and eagerly courted bands in the country, a fact confirmed by the numerous major-label scouts at Friday’s show.

This level of indie rock success used to take years of tireless base-building to achieve. But today it seems the bands that make it are those that get a quick start and build momentum from there. Band of Horses, for its part, has sprung from the gate at a full gallop.

And this is one case where the music lives up to the hype. “Everything All the Time,” released on Seattle’s revered indie label SubPop, is a confident debut redolent of Neil Young, My Morning Jacket, Iron & Wine, and the Shins. Bridwell’s pleasantly pinched voice – thickened by a mild echo-effect – comes through piercingly clear whether the band is playing up-tempo and jangly (“Weed Party”) or soft-spoken and plucked (“I Go to the Barn Because I Like The”).

Their best songs do both, contrasting lulling sections of picked notes and washed-out guitar with thrilling rushes of sound. Live, the dynamic was even more dramatic: The lulls were more lulling, and the rushes – on songs like “The Great Salt Lake” – felt like they could sweep you away altogether.

But the band managed to avoid rely ing too heavily on its one favorite trick. “Our Swords” was a polyrhythmic groove played on duel basses and drums. “Wicked Gil” was quick and Strokes-like, where the warm, waltzing melody of “Part One” lingered in the humidity thickened air. A cover of Hall & Oates’ “You Make My Dreams” was performed so lovingly, with so much obvious care and consideration, that it felt perfectly earnest.

The main set ended with “Funeral,” the centerpiece of the album. It began with doleful minor-key notes, haunted oohing, and regretful lyrics befitting the song title: “I’m coming up only to hold you under / and coming up only to show you wrong,” sang Mr. Bridwell. But it quickly built to such ecstatic highs of machine-gun drumming and headlong guitar that it felt anything but funereal.

Mt. Egypt (nee Travis Graves), wearing an Ocean Pacific T-shirt and a mountain-man beard, opened for the band and was a pleasant surprise. Band of Horses backed him up on unassuming songs that relied on the popping, broken-spring guitar parts of Built To Spill. The lyrics were full of animistic nature worship and surfer-dude Zen: “The wind she is so sweet / she just blows through the trees / and the sun he don’t think nothing at all / he just is and he just does,” sang Mr. Graves blissfully.

He occasionally punctuated his slipshod delivery – which somehow recalled both Bright Eyes and Michael Penn – by throwing his hand forward, rapper-like, in time to the words. But a more common gesture – and a more fitting one – was the hang-loose sign, which he passed over every section of the crowd like a blessing.