Dave - I agree that politeness and respect for the artists is very important. On this same visit there were two chaps stood chatting at the bar throughout the second set - now THAT was bloody annoying and wanted a telling off. But there's a certain kind of stultifying reverence that can be the opposite outcome, where even a few whispered words during tuning up are met by an OTT response from one or two of the "gatekeepers". Maybe it's something to do with so many folkies being school teachers (she said, tongue firmly in cheek...)