If you want to update the accepted definition of folk music, you're going to have to do better than (I paraphrase) - "Folk is anything that washes up on the shore of my club."

Your paraphrase is inaccurate. Better would be Folk Song can be any song sung in the name of Folk in a designated Folk Context. A DFC is not necessarily a Folk Club. Whilst I haunt the amateur fringes of folk, there is nothing in the folk world as a whole (festivals, magazines, record companies, radio shows, internet fora etc.) that would contradict my proposition of Folk as Flotsam, which is to say a generality of music performed in the name of folk and defined by context rather than genre. I say again, I base this on observation of the evidence - I'm not making it up.

So is that another new definition of folk? A solitary pursuit?

How lonely are we Folkies in the real world? How often in the course of our every day lives do we cross paths with another of our breed? Not that often in my experience! Head for the local folk club and no longer feel alone! Kindred spirits and like minded souls! And a network of community, belonging and togetherness brings you into the bosom of the fold. Hell, I even my wife in a Folk Club and how happy I am that we might bring our Folk home with us; I know singers of both sexes who married and were never heard of again. I know others who married outside of Folk and brought their new spouses into the fold where, although they might never sing, are as much a part of it as anything else. And what proportion of Folk is the singing? As oppose to the banter and the crack (I am a Geordie) and the Jouissance that might well come through the music but which is, in actual fact, the consequence of context alone? Hmmmm - Folk is a community thing; I may sing my songs solo (though rarely unaccompanied) but the experience is collective.

If you visited a country and failed to find a folk club that resembles yours, would you conclude that said country has no folk music?

Even the IFMC (who came up with the 1954 Definition) have changed their name to the ICTM; so Traditional music makes greater sense, although their remit does state: The aims of the ICTM are to further the study, practice, documentation, preservation and dissemination of traditional music, including folk, popular, classical and urban music, and dance of all countries. But this isn't about Folk Clubs per se, rather Designated Folk Contexts which in British Society include Folk Clubs, Festivals etc, but in other cultures might be very different as a casual glance at YouTube might reveal. British Folk Music (as we understand it, or don't as the case may be) is not and nowhere near the whole of the case for British Traditional Music or British Ethnic Music, rather something very particular with respect of a Revival largely determined by a particular generation whose musical concerns, as I am attempting to show, are not wholly traditional.