That's Theresa Andersson doing her best 8-person band impression and succeeding with high friggin' flying colors. I'm so impressed, and look how cute she is:
I love her enthused moves, and that black and white flowery dress above is now on my list. Also, her mother knitted her those wrist warmers in the photo on the left out of wool from her native Sweden. Theresa now lives in New Orleans and makes all her music in her kitchen, as evidenced by the video above. The fact that she performs this craziness live is so cool. I'm gonna keep my eyes out for a local performance. I'll let you know when she's near.