First weekend in May, then, in Muenster.Muenster has a youth hostel, top quality near the town center, but wait. I'll ask my wife whether she'll take our daughter with her for a weekend somewhere else. In that case you could bring your sleeping bags and fill our five rooms flat (4 could sleep comfortable, 6 fine, 12 possible,...).
A music pub? Not really my taste, but an Irish pub (and if we go first to some other place for the food, it is fine...)
Wolfgang