Imagine that you're sitting in a food court, or waiting for a train, or shopping in a mall, when all of a sudden, seemingly random people break out in song and dance. This scenario happens around the planet, bringing joy to the participants, the observers, and to people like you and I, who will watch it later on the internet. It's called a flash mob.
Today my joy was courtesy of a flash mob in Copenhagen. Share the joy to strains of Bolero!