A few years back I was lucky enough to see the Venezuelan pianist Gabriela Montero perform. She is a classical pianist. And she improvises. The first thing she did was invite the audience to sit anywhere. Many joined her on stage. Some even sat under the piano.
I am in Cambodia this week, working on collaboration. I was invited only last week, to work with a co-facilitator I hadn't met, for a client I don't know in a field I am completely ignorant of (disaster relief management).