He has composed several major film scores, numerous commercials and TV series, including many seasons of leading BBC dramas such as Hustle, Murphy's Law, and Death in Paradise.
[5] As a producer/arranger programmer and re-mixer, Fiennes has worked with a diverse range of artists including Neneh Cherry, Marianne Faithfull, Gary Moore, the Spice Girls, Bryan Ferry, Hal David, Seal, Yello, Eagle-Eye Cherry, David McAlmont, Ian McCulloch, Roland Gift, Lenny Kravitz, Nigel Kennedy, Daniel Lanois, Trilok Gurtu, Damien Hirst (in the guise of Fat Les's Vindaloo), Dot Allison, Justin Hawkins, Jamelia and Geneva.
Other work includes producing the double platinum Watching Angels Mend for Australian singer-songwriter Alex Lloyd, a collaboration with Canadian violinist Lara St. John on the album Bach with Beats for Sony Classical, co-writing material with Massive Attack and the Sugababes, and co-writing and producing album tracks and singles for Bertine Zetlitz (a Norwegian number one) and Liberty X.
Although Fiennes now works primarily in the field of film and TV composition, he was music director on Shakira's The Sun Come Out 2010 World Tour.
Fiennes has produced tracks for Working Title's Rowan Atkinson vehicle, Johnny English, and co-wrote the closing Massive Attack song on their score for the Luc Besson film, Danny the Dog.