If you get a chance to see the Beta Band while they're on tour, *go*. They were fantastic at the Danforth Music Hall last night. I somehow missed them when they were originally together though I was a huge fan.
All of them interchanged instruments easily, but not particularly slickly: the Beta Band has always been very loose, more about keeping a groove than being tight. They were having fun, and we had the best time.
And yes, from the video screen, they were playing "Dog's Got a Bone".