If you don't know, here's the back story.
The prison is in Singapore I believe, and the Warden of the prison is the son of a former prime minister and brother to the current prime minister, basically he's in a position to do whatever the fuck he wants. So, when guests of honor arrive to the country, the warden would entertain them (among other tourists as well) with dances performed by these prisoners. And, this is true, any prisoner who didn't participate were beaten or punished. There you go, and to add, I believe the prisoners perform at least once a month or so, if not more, with a new dance each month.