I have been considering this further. I have decided that teling people they cannot sing at a tune session is wholly unacceptable, as would be telling people they cannot play a tune at a song event. It is arrogance of an almost breathtaking kind.

I think it is arrogance of a breathtaking kind - to place other people in the position of feeling that they have a choice to either spell-out - what is blindingly obvious - or be imposed upon.

If you had a pub with limited space - it may be convention that on certain nights the pool table was used and on others that it would be covered-up to allow darts to be played in the same area.

It would be arrogance of a breathtaking kind for someone - in full knowledge of this convention - to arrive and insist on un-covering the pool table to play pool - when the rest of people present attended on the understanding that it was a darts night.