I went to college in New Orleans - guys like this are just everywhere; we used to go see this one amazing blues guy who'd play in the sleeziest little corner bar, never could get his act together enough to break into the bigger New Orleans scene. They didn't have a cover but would pass around a bottled water bottle (like a hat). I had a classmate who worked at a record company who got to squire Bono around New Orleans (said he was a nice guy) and that's where she took him - said Bono stuffed a $100 in the bottle. My guess is it went into the guy's arm that night. Sadly, it seems to be what makes the best blues players; the right to sing them.
I loved seeing the Tipitina's shirt on him - if you like this style of piano playing and have not been initiated, Professor Longhair is the tops.This is a great recording of him from the Nice Jazz Festival: http://www.youtube.com/watch?v=PX1vwDe9Z94&list=RDbXZLgJJ7bhQ