One of the great problems with weaker and less experienced performers (crib sheets are an indication of these) is, of course, that they can impact on the performances of others as far as the audience is concerned.
Get a run of three - for reasonable to well performed songs followed by a poor performer, and the atmosphere in the room plummets, leaving the better performers to have to lift it again.
I'm not suggesting that people should be disqualified through lack of experience, but the fact that there are such people who wish to sing has to be recognised and catered for - this can be done by thoughtful M.C-ing.
In recent years in Ireland, 'singing circles' have become very popular, basically bar-room gatherings where the night it turned over to singing - County Clare has a dozen of them, I'm told.
The best of them are the ones with a firm but friendly hand running th proceedings.
Our nearest one is run by the landlady, who, while she isn't a singer herself, is an enthusiast with a good ear.
If things fall into a rut, he will nod or point to a singers who she thinks will lift the proceedings.
Democracy is all very well, but..... 'a camel can be a horse designed by a committee" as they say!!
Jim Carroll