If I may ask; What harm is done to the audience if the singer has a lyric sheet ? If you find it distracting, close your bleedin eyes, just sit and listen. I find a lot of this dogmatic stuff off putting. If it is an amateur folk club, let the participants do what works for them. If you don't like things done that way, go to a club that suits you. But don't bar those who, for one reason or another, have difficulty recalling lyrics, that is just petty, very petty snobbery.