I like to go to the dress rehearsal of the Fiesta dancing at the Mission. It's not very crowded, meaning I have easy access to photograph the dancers.
The year a group of feral kids were having the time of their lives dancing in front of the stage, and sometimes just at the edge of it.
This presented me with an enjoyable challenge... It wasn't too difficult to shoot around them.
What can you do? Enjoy the show and go with the flow.