I come from the school of thought that believes if you're half way through a song and you can't remember it, and if someone prompts you, you still can't remember it then pass on, it's only good manners. On the other hand I can't see the objection to somebody having words with them and using them as memory joggers or even to sing each and every line, as no-one seems to object to dots, i.e. some-one reading music, so what's the difference - forgetting the words or the music? As for professionals, well Sid Kipper and Les Barker read from their lines all the time, and there are times I wish Roy Bailey would do the same. It's an elderly moment for many of us.