One night, about ten years ago, I walked into Cafe Sbisa's on Decatur Street looking for a cup of good coffee and maybe something sweet for dessert.  They sent me upstairs, and as I climbed I began to hear piano music-probably a Gershwin tune, or a Scott Joplin rag. It was good enough that I picked a table near the piano.

The player was a young, white guy with a handlebar mustache, moderately long hair, and a maniacal twinkle in his eye. I ordered my coffee. But as it arrived, and I took a...