Hey, I was at a show that jwz was at! Seems you were awfully close.
How'd you like it? I was very pleased, even as some songs seemed about 75% "singing over an MP3".
There was definitely some backing-track action going on, but I think all of her vocals were live. I thought they were great. I saw them at SXSW last year. I have no idea why they got bumped from being the headliner, especially since everyone left before Katy B came on (who was terrible and utterly forgettable).