Baauer released Harlem Shake in 2012, and it exploded online in February 2013 as a viral dance meme. The format was simple: one person danced alone while others ignored them, then the bass drop cut to everyone dancing wildly in costumes. Thousands of versions appeared on YouTube within weeks, from offices and classrooms to sports teams and newsrooms. The song topped charts during the craze, and the clip has survived as instant shorthand for a sudden shift from calm to chaos.