Near-flawless Mates of State at Transfer

Married cuties Kori Gardner and Jason Hammel sounded dandy in 2003, looked Next-Big-Thing-ish, then never quite popped off, as countless "twee" and keyboard-based indie-pop acts swept in with increasing popularity, notably the similar duo Matt & Kim. But while Mates of State toiled under the radar, their albums got better and better, and their near-flawless set at the Union Transfer on Thursday played like the greatest hits of a band you've never heard.

Harmonizing on nearly every note, the Mates' albums can be spotless and blindingly sunny. But live, they sweat and bleed. Gardner is the organ/synth/what-have-you virtuoso with the photographic muscle memory, re-creating every studio-polished note perfectly with her hair in her face. But Hammel's surprisingly hard-hitting drums added heft. Thrashing his toms on "Get Better," slip-sliding around the winding organ on "Whiner's Bio," and grinding the carnivalesque "Ha Ha" to bits, he provided the crucial bottom end to making all that rainbow-colored treble palatable, not to mention danceable, for a full 90 minutes, as the stomping "Sway" attested. More than one crowd member was spotted playing air keyboard whenever Gardner pulled out a big flourish.

"You're just waiting for the hit, then you're gonna leave," Hammel cracked midway through, after fans shouted for old stuff. They were placated - forgot all about 2004's mighty catchy "Goods (All in Your Head)" - but luckily the band drew heaviest from the recent triumphs, 2008's Re-Arrange Us and 2011's powerhouse Mountaintops.

Those albums provided highlights like the midtempo new wave "Basement Money" and the lovely, intense "The Re-Arranger," abetted by a rarely seen bassist. More prominent was the unannounced, bearded sideman who acted as their de facto hypeman when he wasn't playing shaker, tambourine, or, most crucial, trumpet.

From the peppy textures on "My Only Offer" to a mournful solo on the closing "Mistakes," the guitar-free mix was surprisingly full and varied. The floral stage backdrop and patches of ivy obscuring the duo's instrumental stations were the perfect metaphor for the Mates' unforced cuteness and natural shyness that didn't mar their crafty professionalism, or their capacity to rock.