"I also find it difficult to believe that you have to be a union member to sing in public." Some thing that are difficult to believe aren't actually true, and that is one of them. (And it wouldn't have made any diffeence if we'd all been members of the MU at that press stunt. Which for all I know some of us were.)

Mind I tend to think that anyone who isn't a member of some union is probably opting out of a civic duty, but that's a different matter.