Only because Sr Vitelli's access to the boards is limited, I'll try to answer for him.

He is singing only with them ~ no instruments (although I suppose he plays the organ when he gets home). He said this was his first public singing in over 25 years (at least while sober). He's REALLY enjoying it, though!

He actually filmed some of their recent YouTube vids, but has since been a performer (singing). He said they are getting favorable feedback from passersby, and for a New Yorker to stop for a minute in the subway, that IS a big thing!

It's interesting that the group's banner is spelled out in the same style used to designate the subway's trains (each letter is in a colored circle ~ the same thing you see on the front of the train as it pulls into a station).