I've been invited to a house concert - woo and may I add hoo!

This is a first for me, so I'm wondering what the drill is. I know the time date place identity of guest and suggested donation, but I'm wondering what to expect apart from all of that. Should I bring a bottle? Should I eat beforehand? Basically, how much like a concert (which happens to be in someone's house) is it likely to be, and how much like a "party" ( I believe that's what they're called) which happens to involve a well-known folkie?

And no, I can't ask the person who invited me - behave. I'd be mortified.