Eric wrote: Certainly in England, the natural environment for folk music is a pub...

That is very different from here in North America where much of the folk music scene centers around coffee houses, churches, and schools, which are alcohol free environments. In the great majority of our pubs and bars, if a group of people started singing or started an instrumental session, the owner or manager would ask them to stop. Otherwise he or she would ask them leave. There are of course exceptions, but for the most part we do not have the pub based folk tradition where a UK style fringe can take root. Instead, our informal sessions tend to spring up in the nooks, crannies, and corridors of the festival itself; or in the campgrounds, if there are any; or in the lobbies and lounges of the hotels where festival goers stay. A few festivals even have the good sense to set aside rooms for sing-arounds and jams, sometimes facilitated but more often spontaneous.