Lecturer who played the piano and sang, Celebrity ~2006

I was a passenger on the Celebrity Zenith departing Decmeber 18, 2006. There was a guest lecturer who gave several lectures (one was on Gershwin) that I thought were quite entertaining. I say 'lecture' but he gave them from behind a piano, and much of the lecture was him playing and singing songs. He may (or may not) have been from Philadelphia.

I'm trying to track down his name. Does anyone remember? I tried searching here for Celebrity Zenith reviews, but I have had no luck (probably because Zenith is no longer a Celebrity ship).

Someone who does something similar is Barrington,"Barty" Brown. He's British. We first saw him in Feb 1998 and then happened to be on the Emerald Princess with him in the fall of 2010, I believe. I've been trying to find what ship he's been on since then. HELP.

Thanks! Lynne