If there existed a music festival featuring only girl/guy duos, the White Stripes would certainly be the headliners, and I Am The World Trade Center would probably get the most people dancing. Quasi would get a big crowd, too. But for sheer entertainment value, Mates Of State might steal the show.

On a recent tour opening for Rainer Maria, Mates Of State (a.k.a. singer/keyboardist Kori Gardner and singer/drummer Jason Hammel) provided its share of the evening’s entertainment. The San Francisco duo’s 45-minute set included about half the songs from last year’s Our Constant Concern, including “Hoarding It For Home,” “10 Years Later” and “Quit Doin’ It.” The handful of unfamiliar songs Gardner and Hammel previewed didn’t break any new ground, which is fine, really. Mates Of State have already distanced themselves from the pack by offering the rare combination of uncluttered drums-and-keyboard music and off-kilter vocal harmonies.

Watching Hammel drum is part of the show; it isn’t often the audience gets to really focus on the drummer, who’s usually obscured behind a wall of guitarists. The lanky Hammel whirls his arms like helicopter blades, and because the band’s sound relies so much on precision start-and-stop tempos, he spends an inordinate amount of time grabbing hold of the various cymbals on his kit to mute them at the appropriate time.

But the evening’s highlights were the 360-degree twirls performed by Gardner during “A Duel Will Settle This.” In the second-long breaks near the end of the song, she rocked back on her heels and spun around, arriving face-forward again in time for her hands to land on the next keyboards notes. Mates Of State don’t have the swagger that propelled the White Stripes to critical mass, but they’re having fun getting there.

—Peter Stoltz