'Have a look at the book about the Elliots of Birtley when they say "We di'nt know thst we were singing folk songs till Ewan Maccoll told us"'

But the point is that they were singing folk songs. Just because they hadn't put a particular label on them didn't mean they wern't folk.

There are two aspects to this argument: the purely academic one which is of only passing interest to the ordinary music lover, and the more practical one of what sort of music is appropriate in a "folk club". The latter is important, because there is a case for saying that too broad an approach has contributed to the general decline in folk clubs.

I don't know of many clubs which had an actual policy, but most were self-selecting and the division into trad and contemporary clubs was more a matter of natural selection than edict. If a club doesn't want to book a performer because they don't suit the style of the club that's not being "purist" or "fascist", that's just paying regard to the expectations of the club's audience.