"If you don't want people singing along, tell them so right up front"
You shouldn't have to - if you need to do it you imediately set up a barrier between yourself and your audience.
We've even had it on this forum "what make you so good that you don't want us to join in?"
Surely it is somple good manners to wait to be asked?
I agree totally with Suibhne - it seems to be soem sort of ego trip - actually encouraged in some clubs.
To me it is arrogant, bad mannered exhibitionism.
Jim Carroll