The Love of Music

Recently I saw a video of these two strangers in an airport. One of them is playing piano by himself, and a lot of spectators watch him play. Soon after that, a complete stranger walks up and watches the man play piano. As he watches him play, the man watching chimes in to play as well. This is called improvisation. Where a spectator watches a man or woman play piano, and chimes in to play with the entertainer. It's completly normal for a person to play along side a piano player.