...if Fred always sang a particular song...

Personally I would consider Fred discourteous and lazy if he couldn't be bothered to learn a new song. After all he has had a whole week or even a month to learn it.

What is with these people? Part of the fun and one of the reasons for going to singing groups is the discipline of learning new stuff.

BUT, if I knew that he was going to sing it at a session then I wouldn't sing it. There is so much other stuff out there.