The most-played song on UK radio this century - 'Chasing Cars' by Snow Patrol

The lovestruck ballad never reached number one in the UK, but remained on the charts for more than three years, and it took up a similar residency on the airwaves. Gary Lightbody told the BBC how they wrote the song "in the shed of his [producer's] garden" where they "went down with a couple of bottles of wine, and we wrote through the night". The second most-played song of the 21st Century on UK radio is Black Eyed Peas' 'I Gotta Feeling', and Pharrell's 'Happy' third.