Tricky one, this... I suppose it depends upon the reason why the person is singing... if they are singing for their own enjoyment primarily, then they sing what they enjoy. If the primary concern is entertaining others, then a little 'audience savvy' comes into consideration.

People who attend singarounds are usually there primarily for their own enjoyment, so are entitled to be a little 'selfish'.

Having said that, it irritates the hell out of me seeing/hearing someone sing the same song every time I see them, and reading it off the same pice of paper with a page turn in the middle of a verse!!

A good job we're all different, innit?!