LIVE: Kat Edmonson @ Tanglewood, 9/6/09

We love a good surprise.

And we found a real doozy at the Tanglewood Jazz Festival on Sunday afternoon in the form of the Kat Edmonson Sextet. Not only did we not know anything about the stunning jazz vocalist and her band – she was a last-minute substitute booking at the fest – but we’d never even heard the name before we found her at the microphone in the Jazz Cafe tent.

But it didn’t take long for her to win us over. The pixie-ish 26-year-old Austin jazz singer was slipping into a gloriously languid rendition of “Just One of Those Things” as we arrived, and she followed it with an equally dreamy rendition of “Angel Eyes.”

She didn’t linger exclusively in the world of standards, however, and some of the other highlights of her set included John Lennon’s “(Just Like) Starting Over” and Carole King’s “One Fine Day.”

Of course, it didn’t hurt that her band featured some excellent musicians, including saxophonist John Ellis (who was leading his own band at the Freihofer Jazz Festival at SPAC earlier this summer) and pianist-arranger Kevin Lovejoy (a former member of alt-rock faves Spoon, as well as John Mayer’s band).

But it’s Edmonson’s restrained, soothing voice and open-minded repertoire that makes her music so captivating. In a preview of the Tanglewood fest, Boston Globe jazz writer Steve Greenlee declared last week that Edmonson would be “the performer everyone will be talking about once the festival is over.” And we’ll agree with that.

He also wrote, “Edmonson might be the most promising American jazz singer to come along since Cassandra Wilson.” And, yeah, we can dig that, too.

So keep and eye (and ear) out for her, or better yet, grab yourself a copy of her recent debut album, “Take to the Sky,” which also includes her exquisite interpretations of the Cure’s “Just Like Heaven” and the Cardigans’ “Lovefool.”

Photos by Andrzej Pilarczyk.