This dance is rehearsed using volunteer dancers from the local area, before hand. They have one evening of learning it fully clothed and another (in private) practising it naked, before the performance.
The finale is when females of the audience are asked up to go behind the curtains and strip naked, the curtains then open to reveal them and they all sing an anthem naked!
I have the same videos as the poster above (including a finale!), I'm having trouble posting, so perhaps he might be able to oblige. At Lancaster, most of the dancers were late-teen students from the Uni it was being performed at!
