Pip Radish: "I think the experience of the Lewes Arms club shows that it's not necessary to explicitly ban or discourage bad performers, but also shows that it is necessary to have quite a lot of peer pressure, in the shape of a lot of good performers. On another thread you (Snail) objected to the idea that you discourage bad performers, but I think that is what you do - not directly, simply by putting on a lot of good performers who they're forced to compare themselves with."

That makes perfect sense to me.

I would also have thought that subtle cues given by the individual running the club, might be quite enough to tip the balance towards generally improved performances? When I went to a club recently, the organiser asked me to sing again at the end. This of course makes me feel positive about the efforts I have made thus far, and it motivates me to keep making the effort to do the best job I can.
Extrapolating from this, I imagine that exercising a simple and subtle psychology of public 'reward' (however small) for those evident efforts individuals do make, must I think inevitably (eventually) encourage those who are perhaps 'just going along for the ride', to dedicate a little more time and effort to making the best of the pieces they plan to do in future?