I've never found much in the way of live music for dancing other than Foxy's Halloween party, maybe a bit at Leverick's BBQ, the Festival in Road Town in early Aug, and once at the old Jolly Roger in Sopers (an awesome party!!). (I've never been in high season. Our trips have been always been between April - November)

Most of the spots you listed are pretty low key, BYO party kinda places.