It's been said more than once up thread but apparently still not digested by some posters. "Crib sheet" can mean different things.

Something to be referred to for an occasional reminder if there's a memory lapse is one thing. Some singers who don't use them for that purpose should.

But if it means only half knowing the words or not knowing them at all and having to read them all the time, then it's something quite foreign to most of the singers from whom the songs were collected and to general practice in folk clubs in the earlier years of the revival, and it is justified only in exceptional circumstances.

One such circumstance is when a good song writer is trying out a new song. But that should only be with a sympathetic audience in a club that really is a club, where most of the "audience" are participants. Another is someone being asked to sing a song that is not part of their normal repertoire, for example in memory of someone who has just died.

Apropos (thread drift) tuning when about to perform: I only wish all guitarists would do so, and thoroughly. Never mind extreme temperature differences caused by stage lighting: instruments drift out of tune even in normal room conditions. I have often heard what would otherwise have been an excellent performance ruined by the performer not taking enough time to get the b---y thing in tune first.