I sometimes do a sort of demo also. I just turn on the drums and start "introducing" the band. I bring in the bass man, then a guitar strum, then I play a piano riff, then a ride on sax and/or guitar or organ. It generally goes over quite well. At least they know I'm in control because the "band"
just comps while I talk and I even throw in a mistake or two and tell them that it's on purpose because someone is always looking for something wrong and I want to please everyone.
This works best is smaller, more intimate, settings, where people are actually listening in the first place.