I have shared this before but it may be useful to post it again (figures may differ slightly - I don't have my survey figures to hand).

Based on my experience of visiting about half the 'folk clubs' in the UK (not all of whom use the word 'folk' or 'club' in their title, but who are generally accepted to be FCs), and my notes from phone conversations and web discussions with the organisers of the remainder, I'd hazard an educated guess that the number of places which major specifically on traditional song (where you'd hear perhaps more than 80% trad through the year) to be only about 30% of clubs. (Note that I'm using trad to mean proper, old, public domain material, not popular newer 'falk' songs [falk = fakefolk ok?]

In perhaps 25% of clubs nation-wide you'll encounter almost no traditional material at all.

I should say again that during the years when I used to offer a choice between trad, contemporary or original 'folk' material, I was only twice asked by the organisers to major on trad - and on both those occasions when I asked the same question at the start of the show the audience voted against trad. Even when playing in specialist trad clubs (which I often was), where the organisers anticipated a vote for trad, people voted for original material or whatever I fancied doing. I only did my trad-only set one single time (I can't remember where, now).

My personal experience of the much-more-difficult-to-quantify open mic/unplugged/song-session type of gathering would be that trad material would be less than 10%. Proabably a lot less.

I think we all know that tune sessions, by contrast, would pan out at well over 90% trad.

Tom