What we have here is a failure to communicate. To most practitioners of the English language, "Members, Guests,and Families" means exactly that. Closed club, private party, stay out. You need something more like:

"Whitby Ballad Venue 2002: Thoughtful traditional singers and listeners only, please!" Or, leave the room open, but spend a few euros and have a bouncer in there escorting jerks out.

Or something like that. O'Flaherty's in New Orleans has a main rowdy pub and a Ballad room, where you are warned with tactful signs and by the doorman that the loud will be removed. It works well, despite the constant influx of unwashed humanity from all over the world which passes through there.