John C., My fail-safe system kicks in when I do songs I shouldn't do. We've been married 34 years and she has no reservations as far as telling me "don't do that song". I don't always listen though.
I cannot do Piano Man properly. I have to either start it so low that it sounds bad, or modulate on the chorus, and then go back down for the next verse. There are others of course. We can't all do every type song.