The question should be not how "folk" should be defined, but what sort of music one can expect to hear at something describing itself as a "folk club". For at least 50 years (from my own personal experience) this has always been considerably wider than only traditional music. The meaning of the term has also widened from when it was originally coined by the early researchers into folklore and folk music - this may be regrettable, but how language evolves is out of anyone's control. "Folk" no longer means traditional music, although it of course includes it, and hasn't for decades.

The exact balance has always varied from club to club. Even back in the day there were clubs who specialised in the sort of "contemporary folk" which essentially means a singer-songwriter with a guitar - not my cup of tea, but fitting in with what the general public now understand by the term "folk". It would be unusual to hear a traditional song in those clubs, but in those days there was probably another club nearby with a different balance, so there was plenty for everyone.

I understand and sympathise with Jim's frustration at going to a "folk club" and not hearing a traditional song. Especially if what is being performed is stretching even the wider popular meaning of "folk", when it should probably be more accurately described as an "open-mic". However old habits die hard, and an open-mic event might imply an emphasis on popular music and actually put off someone wanting to perform traditional or even "folk" songs. At least these days many clubs have a website or Facebook page where you may be able to get some idea what to expect before you go.

Times have changed. Yes,there are far fewer folk clubs, and many of the old clubs are struggling and have had to adapt to survive, and this may not always be for the better. However there are still opportunities to hear and perform traditional songs. Plenty of young people are involved in the music, they are just doing it their own way (as our generation did) so there is no need to fear for the future of folk music, even if it may not resemble what we are familiar with (which would have been equally unfamiliar to previous generations).

Thanks to Rod Stradling, Topic, Veteran Records and others there are more opportunities than ever for people to listen to traditional singing and playing, and again young people are taking advantage of this, as well as listening to our generation who had the opportunity to hear it directly from traditional singers when they were alive.