Gangnam Style inspires copycat videos
Rapper Psy has become the first South Korean pop star to make it to the top of the UK singles chart with his song Gangnam Style.
The track has become a global phenomenon and the video featuring his famous horse-riding dance is YouTube's most "liked" of all time.
It has also inspired people around the world, including prisoners in the Philippines and Thai navy personnel, to hit the dance floor, as Clive Myrie explains.