IMHO Folk Music is a valid category wether paid for or not, my original thought was at what point do you fully cross the threshold into another style - Blues, Jazz, Pop? If I performed Fernando by Abba on acoustic guitar is that a bit to 'Folkie' for a session promoting a wider approach, or it just a sweet pop song?

When I first heard 'The Downeaster Alexa' by Billy Joel from a library cassette (remember those?) I felt completely at ease performing it in Folk clubs because of the subject matter ( sea, hardtimes, a dying lifestyle).   

Skipy, you correctly indentified the Session at WHF, I now realise I have an extra week to ponder this conundrum!

I certainly look forward to some great pop, jazz, gospel whatever, and as I have that extra week maybe I'll try some Captain Beefheart (Spotlight Kid).