When Kim Min-seok gave the go-ahead in June 2016 to publish a 90-second clip of a children's song, he had no idea what he was unleashing. It became a global phenomenon, clocking up more than 16 ...

Sometimes a song becomes so widely-known and so insanely catchy, it’s impossible to remember what life was like before it. These earworms only pop up every few years, and their expertly-crafted hooks ...