Ooh - not sure I can entirely agree with you there snuffy - that 'shut up and listen' and 'folk' belong in different universes...

Cast your mind back to the days when a bard would sit in the hall and sing to a rapt audience - singing people's lineage, of battles, of heroes - because they were an oral society and the carrier of the stories was held in a sort of wonder - isn't that an enormous part of what the 'folk' movemnent draws its heritage from? If, in the flickering firelight, the drama and tension created in the telling of Beowulf was ruined by someone deciding to 'join in by tapping annoyingly on the table or blowing bubbles in their drinking horn', I'm sure someone would have had something to say - even if the tapper or bubble blower thought they were contributing positively to the atmosphere!

And when a new person would arrive in a village with songs from where they came from and the villagers would listen because they were new stories and (probably) because they were glad of a new voice singing

Personally, I don't think that it should necessarily be the case that 'folk' means all join in together. If I was having a conversation, lets say, I was telling a story or a joke, with someone in a pub, I would take it amiss if someone else just butted in or talked over me.

Why people have to join in with every darned tune is beyond me - surely knowing when and how to listen is as great a skill - and a good opportunity to learn stuff too