About Market Rasen - it describes itself as a folk club, and sounds from your description, Villan, a lot like a folk club. This particular species of gathering wasn't the subject of the question or the answer, so maybe that's why it doesn't quite fit with my description of an Open Mic. You may call it an "Open Mic", but it sounds as if you run it more like a folk club, with a fair amount of organisation, and booked (paid?) guests sometimes. If unbooked, impromptu acts can't get a spot, I'd say it was more of a Closed Mic.

When we're talking about a folk club, there's generally a lot more variety of performers than if it's just a case of unbooked singers turning up on the night and doing their stuff - which is where all the men with guitars come in. Don't get me wrong, I've nothing against men, or indeed guitars (I have one of each myself!), I just find that Open Mics tend to be a bit lacking in variety.