Surely you want folks enjoying the band and dancing around having fun?
Last thing you want is everyone standing as far back as possible and not moving at all, unless you're doing free jazz when you'd be most happy to have your own Min Tanaka (check him with Derek Bailey!) to temper the surfeit of polo neck chin strokers!
Or is only one type of dancing allowed, of the kind that doesn't draw too much attention to the dancer, like a dance equivalent to root-and-fifth?
Perhaps I'll have to have a word next time we're in Hereford and those mosh-boys decide they want to do the can-can like last time...