What I find confusing is that Jim sometimes insists that "folk" means "traditional"., but he then admits that folk-like songs are acceptable, and that one of his best nights in a club didn't have much to do with "folk". So the question then is where to draw the line between "folk" and other forms of music. That boundary will always be vague and to a large extent a question of personal taste. However if you regard traditional songs as having a particular quality because of the way they have come to us, then the only distinction between composed songs is one of personal taste. You may prefer a McColl song over one by Donovan because one is closer to folk forms, but that doesn't make it a better song.

Personally I could never see what connection there was between say Nick Drake or Donovan, or Simon & Garfunkel for that matter, and folk, except that one interpretation of "folk" has come to mean a singer-songwriter with a guitar. That's possibly of American origin, in the Woody Guthrie tradition, but whatever its origins it has stuck.

I think what is acceptable to put before a folk club audience depends at least as much on content and attitude as provenance. A song with a message or a story, with words up front and with a connection to the audience will often go down well. As for actual pop songs , it depends on context. If a floor singer started to turn up at a club and sang only pop songs every week, then no matter how good they were someone should probably have a quiet word. When an established performer of traditional songs throws one in, it's a bit of fun and not meant to be taken seriously - lighten up. Or sometimes a different interpretation can shed new light on a song - I think the Tabor/Oysterband cover of "Love will Tear Us Apart" is streets ahead of the original because they make it feel more personal, but I know many will disagree.

I don't think any folk club audiences want to hear a night of pop songs, but in my (admittedly now limited) experience of folk clubs I don't think this happens very often. I think Jim may have been unfortunate in his own experience of modern clubs. Where I do agree is that poor performance standards are a greater threat. I can't see why anyone would want to submit themselves to that, except for the opportunity to sing themselves, and I don't think they are a good advert for folk music. However in places where good standards are encouraged I think they are higher than ever, as singers and musicians now have far more opportunities to obtain instruction.