I can predict the future. These are all the winning lottery numbers for ALL the forthcoming weeks -
1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49
All you have to do is pick out a few each week...

We have a very well known and supported Folk Club in the Black Swan in York (mostly a concert venue with a singers night once a month) but Roland has his hands full each year - and a measure of risk - in choosing a diverse range of acts across a year that will attract bums onto seats and keep the clubs finances on an even keel. He manages it very well but he can't really predict what works and what doesn't even with his (good) judgement based on years of doing it.

It ranges from unaccompanied singers (Hissyfit were well received and supported recently) to bands either at the pub or at a larger concert venue.

There are buckets of people though who come to something like Steve Knightley playing in our local village hall (I know a fair number of people but recognised perhaps a tenth of the audience). There are a whole other group of people who go to festivals and pubs and see a band like this - Holy Moly and the Crackers who you would not see at a folk club. And you probably wouldn't see the (young) people in the band at a folk club even if their roots are (self professed) in folk amongst other genres. I pick them because I know some of them through my son and have enjoyed a sing with them in the past in a local pub and at a party in their house; they are typical of many similar groups of people appealing to people of a range of ages.

I think this discussion has been had many times on here.

Folk clubs have this weird personality disorder. To those who don't go to them they have an image of jumpers, beards, fingers in ears and long unaccompanied dirges with lots of death; they aren't. To those who used to go but don't so much they are places that have become divorced from their roots of proper folk music because its purity has been tainted over time; they probably aren't this either. To those who go they are curious mix of wannabe players who may either be good or not supporting artists who will put bums on seats and be something linked to a broad definition of folk.

I'm sure that the ones that do well are the ones who have a very clear idea of what they are doing and delivering to a known (and hopefully evolving) audience, and have a clear idea of market they are in without a need to compromise their vision. Whatever that vision is.

I haven't been to Lewes but, from the outside, am pretty sure that they will survive and grow as they seem very clear on what they do. The Black Swan will keep going for as long as Roland and his team of helpers and supporters choose. Somewhere like Wigan folk club (which I haven't been to for a long time) was a very well supported but very different sort of place. Swinton was another that comes to mind.

My personal experience has been that it is difficult to maintain something that is relatively broad church. There seems a constant pressure for factions to convert a club/gathering into their particular narrower passion. Depending on how popular that particular interest is to other listeners is where it either succeeds or falls on its ass.