Focus, with the amazing, yodeling, whistling, seriously high piano player. When you first get a good look at him, 22 seconds into the video, he looks like he's on the verge of a seizure! Then, when he lets go at the 1:00 minute mark, you realize that he's probably got to be that intense to carry off this performance. Excellent video, classic 1973 cutting-edge stuff.
Hocus-Pocus, Whidbey Island.