“Gangnam Style” is the 18th K-pop single by the South Korean musician Psy. The song was released on July 15, 2012, as the lead single of his sixth studio album Psy 6 (Six Rules), Part 1, and debuted at number one on South Korea’s Gaon Chart. On December 21, 2012, “Gangnam Style” became the first YouTube video to reach one billion views. The phrase “Gangnam Style” is a Korean neologism that refers to a lifestyle associated with the Gangnam District of Seoul.

Source: https://en.wikipedia.org/wiki/Gangnam_Style