Bert, who gave you the keys to the rule book? The session I grew up with allows anyone to play anytime they like, if there's a gap (with attention being paid to any player who looks like they'd quite like to lead a tune, of course)... a "jam" doesn't exist in the folk world - that's something that jazz (*pheugh*) and blues players indulge in.

Making everyone have a turn puts players under pressure - I have seen people get quite flummoxed when the session "leader" suddenly points their finger at someone and expects them to churn out a tune on demand. Sessions are organic and should be allowed to evolve, and at the risk of repeating what the more sensible people on here are saying, if the music belongs to a tradition you don't relate to, or the playing style is 1) foreign to you or 2) too difficult for you to play, then how hard is it to wander off to the next session, or indeed start a new one??

Anyway, I've been irritated by this band of upstarts for years and years. It's because I don't stand a hope of keeping up with them for quite a lot of the time. But by playing with musicians like these highly talented individuals (who incidentally only really see each other at a select number of festivals over the course of a season) my own playing has been pushed really hard and allowed me to take the sort of massive strides I'd have had to pay a lot of money for otherwise.

Breakneck Horizonto anyone? Or maybe the classic Sir Sidney Smith's Race? *choke* sorry, I was forgetting. That might just be FUN!