Everything that lingers in the background of the Brooklyn band Yeasayer's recorded work was shoved notably to the forefront when the lively quartet blossomed in the basement of the First Unitarian Church on Thursday.

Some of the expected Middle Eastern and tribal tinges were downplayed, and the players didn't summon Talking Heads so much as some otherworldly bog steeped in heavy psychedelic vibes. There were bewitching vocal harmonies, jumbles of world music, smatterings of new wave, and random shards of synthesizer, falsetto, and other musical melodrama.

Part of the latter could be attributed to bearded singer Chris Keating's fleshy yelp, though Indian-born guitarist Anand Wilder slunk nimbly though lead vocal duties on several more folk-influenced numbers. Mixing an equal portion of newer songs with infectious standouts from

All Hour Cymbals

, the band's breakout debut, Yeasayer benefited from a captivating drummer and an on-stage comfort level that became more apparent as their chameleonic set neared 1 a.m.

There was a definite increase in energy throughout the set, from the '70s-ish "Wait for the Summer" and the prog-y depths of "No Need to Worry" to the engaging single "2080" and the trance-y, dance-y closer, "Sunrise." There was a brief stab at a mosh pit from a few members of the audience, who later waited for close to 10 minutes when it looked like Yeasayer would emerge for an encore. Once the house lights finally came on, though, it spelled the end of a thrilling night of music that continually kept the crowd guessing.

Opening were fellow Brooklynites Chairlift, who similarly progressed from sleepily downbeat to engagingly extroverted, as singer Caroline Polachek projected her ethereal voice more with each song. The band's surreal cosmic pop, loaded with vintage synthesizers and anti-consumer sentiments, filled out and became increasingly lively, especially with the buzzed-about tune "Bruises" - featured so prominently in the current iPod Nano commercial - although the closing "Planet Health" was a sultry and inviting communiqué to the 1980s.