Snow Patrol are amazed they write successful songs.

The 'Chasing Cars' hitmakers admit their approach to songwriting can sometimes be viewed as less-than-conventional, with frontman Gary Lightbody unable to even write music.

Asked how they suddenly found success almost 10 years after they formed, Gary said: "I learnt how to write a chorus. The first two albums don't have any.

"But it's not as clear-cut a formula - I will just guess my way through the chords. I don't know how to read music - we write very slapdash - if anybody ever saw the writing process they'd say, 'How the f**k did you ever write anything?"

Meanwhile, the singer says the key to the band's longevity is a firm friendship.

He added: "Never start a band from an advert in a magazine. If it comes together naturally than you've got a bigger chance of lasting. We love each other and we hang out together when we're not on tour."