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."
Duffy in The Sun February 29, 2008: "I'd achieved everything I'd wanted to achieve on the album at that point and I just wanted to let loose. I wanted something sexy. It's about sexual liberty, being young, morals, temptation, all that kind of thing.
I just love organic sound. I love strings. I love the way chords can be cleverly arranged. The '60s was the best era in music and it's a real honor for me to think that it nods to that but it was never an intention. I also love the '70s, the '90s and so on. I remember when I was a child we used to listen to (DJ) Steve Wright on Radio 2 when he'd play that real heartbreaky music. We were just hooked. A bit of drama on the weekends."
Duffy told Q magazine May 2008 about this song's video and the influence of Rita Wright's "I Can't Give Back The Love I Feel For You" on it: "It was because of that song I used Northern soul dancers in the video for Mercy. Some of them are in their 20s and some of the older ones used to dance at (Northern soul Mecca) Wigan casino all those years ago. They explained to me why they love this music. They said it was about the emotion. It's not about the beat. It's the emotion and the passion. They're dancing to the words. That had a massive influence on my music."
This was named Song of the Year in the 2008 Mojo
Honours List, one of many awards Duffy earned. Rockferry
won for British Album of the Year at the Brit Awards (beating Viva La Vida
by Coldplay), with Duffy also winning Best British Female Artist and Breakthrough Artist. On the other side of the Atlantic, Rockferry
won a Grammy for Pop Vocal Album of the year.
This song was #1 in 10 countries in total plus the Eurochart Hot 100. Among the territories this reached the top spot in were Germany, Greece, Holland, Ireland, Norway, Spain and Switzerland.
Duffy told Mojo
magazine January 2009 that she'd spent four years working with various collaborators on a number of tracks reflecting on what kind of record she wanted to make, but still felt something was missing and this song was that missing thing. The Welsh singer added: "We were writing it at the last minute, when the strings were being put on "Rockferry
" and "Warwick Avenue
Duffy told Mojo how this song was penned: "I'd already written the lyrics to Mercy, it was like this melodic poem in my mind, which I just had to get out, and I knew exactly what I wanted it to sound like. Steve was very patient. He sat at the piano and put chords underneath it and we built the song from the bottom up. It's very important that my songs start from an organic source, rather than a drum loop. You can dress it up how you like but at the end it's about the strength of the song, the melody and the words."
"The lyrics were about having a feeling towards someone, whether it's a romantic feeling or just some chemistry that you don't want, and you desperately want to be released from that feeling," Duffy continued. "I'm very cautious about saying what a song is about, it's my issues and baggage and when someone else listens to the song it isn't about my baggage anymore it's about their baggage. I don't want 'Mercy' to become more about the situation that inspired it than the song. The song does the talking."
This picked up the award for Most Performed Work at the 2009 Ivor Novello awards. Since its release, the song has become a staple in karaoke bars.