Back in 2007, Robin Williams was in Kuwait for a USO tour with the military. Most of the soldiers he performed for were either headed to Iraq or supporting combat troops already there.
In the middle of a comedy routine, a trumpet began to play and the entire audience suddenly made an about-face and turned towards the flag.
It was “Retreat” — a signal that the American flag was being taken down at the end of the day. Williams had no idea what was going on. But when they explained it to him, he went with it and was brilliant.