I often find myself watching the audience instead of the actual performance. In reality, they are part of the performance as well. I enjoy being witness to the role that they play in something planned or scripted. Their reactions, the way their faces change, how they hold themselves, if I can feel them feeling me watch them as they watch the performance. The collective emotion that comes from them as they physically and emotionally respond to what they're watching.
It tells you so much about each person and people overall.