So what Pink Floyd was playing in Venice Italy they stumbled across a street performer who's playing what I think it's called the glass harmonica. it's wine glasses with wet lips that are tuned so you can play complicated music on it. They got them on stage the next day. It amused me.
Here's some more links to people cell phone cams the concert.
https://youtu.be/p-kN-0uu0MY
https://youtu.be/IC1ePnrjqU0
it's almost as weird as Frank Black from the pixies being called on stage to play with Arlo Guthrie. Mind you that happened, and it was in Tallahassee.