Those of us in US at least have a number of traditions, and sitting quietly while someone else sings is not probably the norm. And neither is it the only way in the British Isles. How do the Welsh sing? How do the Cornish? Farther away, how do the South Africans? How do the Germans? Russians? There is just not one tradition from which it is rude to deviate. It is up to people who organize these groups to let people know what the rules are they are singing under. I like the Welsh rules myself. First, work in a coal mine. THen come up from the coal mine singing. Sort of leaves most women out but oh well..a small price to pay for not having to work in a coal mine. mg