Here's some info. I've found:
Atlantic Dance is open five nights a week. Tuesday through Saturday there's a DJ Dance Party with open requests. Closed Sunday and Monday. Open 9 p.m. to 2 a.m. There's NO cover charge and you must be 21 to enter.
Jellyrolls: A sing-along bar, with dueling piano players who take requests. Weekends can be SRO, so try to get there no later than 9! Jellyrolls is open from 7 p.m. to 2 a.m. nightly. There's an $8 cover charge, but no drink minimum. Must be 21.