I caught a bit of it last night (our local PBS station shows Austin City Limits on Saturday); it was Shelby Lynne. I was disappointed, mainly because I remember her voice knocking me out years ago when she sang on a chart hit for George Jones ("If I Could Bottle This Up") while still in her teens. She doesn't need to strut her stuff or put on a persona, she's got (at least had) the vocal chops. Another one ground up and spit out by the corporate music machine, I'm afraid.