What's this about setting out rules for music, folk or other? Music (and folk music of course) has different purposes: to uplift, to calm, to praise, to evoke, to educate, to relax, to call to a common cause, and yes, sometimes also to entertain. These can sometimes clash - a dirge has its purpose, but don't ask that it should be "fun"! Especially when, as Declan rightly says, people's idea of fun sometimes can be superficial, or in any case vary widely.

Accordingly you can have folk music events serving different purposes. Some clubs (St Albans Windward is an example) focus more on the entertainment aspects; others, like Herga, like to emphasise the educational, historical, preservational aspects while also keeping an eye towards fun. It doesn't make one club good and the other bad, just serving a different mix of objectives.