Atlantic Dance is still open. Music is mostly DJ driven (as opposed to live music). Different styles on different nights, but it's open-request format, so what you hear depends on the crowd.
The Hall is open Tuesday - Saturday, starting at 9pm. 21 and over ONLY.
We went for the first time last July and were shocked - us and another couple were the only people in the place. It was around 11 o'clock. The bartender was extemely nice and told us he usually works at the ESPN Club, but needed to fill in that night and told us that the crowd level was nomal, unfortunately.