candidate: Since then , she has gone on to work with many artists , including Jewel , Courtney Love , Gwen Stefani , Alicia Keys , Celine Dion , Blaque , Sugababes , Lillix , Robbie Williams , Melissa Etheridge , Sierra Swan , Solange Knowles , Gavin Rossdale , Juliette and the Licks , Lisa Marie Presley , Fischerspooner , Unwritten Law , L.P. , Kelly Osbourne , James Blunt , Cheap Trick , Ben Jelen , Enrique Iglesias and Giusy Ferreri .