A bus stop with swings
Except the truth is even better. This is in montreal and every summer they put up a series of musical swings. If you look in the background you can see more people swinging away.
Each swing is a set of four and has its own unique sound, but if you are in perfect harmony with the other 3 seats then an actual song is played. The theory is that you communicate and interact with people more if it’s for a specific goal and if you’re having fun