"Expecting to know what to expect at a folk club"

It's never been the case that all folk clubs have soley focused on traditional song, accompanied or otherwise, although there may have been more of it in the past.
Over the years I've heard lots of blues, jazz influenced music, "folk rock", contemporary singer songwriters and so on. Even comedy, although I'm glad that's not as much to the fore...the great Billy Connolly honed is act in the folk scene but, unfortunately, he encouraged a lot of imitators!