Saw this show today - very impressed. Thought I'd grab a shot near the end of the final dance. I needed a high ISO as the theatre was relatively dark. The shot needed some processing to get rid of the shadow of the person's head in front of me.
I used NoiseNinja to reduce the noise from using a high-ish ISO. (1600)
Canon EOS-1D Mark III, f/2 @ 100 mm, 1/2000, ISO 1600, No Flash