SINGSONGS.COM | Backing Tracks | Professional Authentic Backing Music

This was written by Duffy along with Steve Booker, who produced the track. She told the BBC how she hooked up with Brooker: "I met Steve Booker by compete coincidence. I was looking for somewhere to live about a year ago, knocked on a door, met a songwriter, went to a studio and had an amazing two weeks writing the two last songs on the record."

Apart from the limited edition single "Rockferry ," this was Duffy's debut release. It was therefore a remarkable achievement for "Mercy" to enter the UK singles charts at #1 on download sales only.

The front cover of the single was snapped at the small coastal village of Porthdinllaen in North Wales.

Duffy told the Daily Mail February 22, 2008: "It's about the way my heart rate increases whenever I leave Wales to go to London."