Yes to the piano bar---sort of. They have music in most lounges and a piano was playing in one on our last cruise
Naturally the main dining is no additional charge along with the Windjammer Cafe. Sorrentos is no additional charge...and good pizza. The Book Nook offers snacks along with free regular coffee. Small charge for Johnny Rockets and then your normal charge for Portofinos and Chops. Then there is Ben and Jerrys for a charge.
Not sure who any of the musicians were on board...sorry about that. I also used the internet but I forgot the rates. We had a discount because of our Crown and Anchor membership.