Davis musician Colin Stambusky and his band Sucker Punch headline a grand-opening Halloween Ball on Friday, at G Street Wunderbar, 228 G St. in downtown Davis. Also on the bill are Avenue Saints, Chickee Bob and Steve Mahoney. The free show starts at 9 p.m.; costumes are welcome. Guests must be 21 and older. Owner Chris Armanini has installed a state-of-the-art sound system at the refurbished bar/restaurant.