Here is a video of one of the ballrooms where some dancing was happening.

 

There was a lot of activity at this venue. They had four floors of things happening. The event had hired actors and actresses to dress up in various costumes. They had dancers who went out on the floor to entertain and entice people to dance. Three bands each on a different floor. A guy on stilts.
These dancers grabbed a couple of people from the audience to cut a rug out on the floor. But there were some regular people who were very good.