I'll quote Mr. Dore's email:

This is an e mail from me to all the people on Sue Malleson's list of (folk and other) unaccompanied singers.

There is clearly such a demand for a regular singer only (no instruments) session that we are starting one every Third Tuesday of the month at the Crown, Market Place, Stony Stratford, from 16 October onwards at 8.30.

It is in the room on the left which has a wooden floor, excellent acoustics, plenty of seating, not smoky, and real ale.

The new landlords Lindy and Steve are really supportive, and the signs are that there will be a big turnout for the first session.

If you know any other singers who would be interested please bring them along.

So I suspect smoking isn't banned, but there aren't many smokers in that lot anyway. But it's definitely instrument-free...