With combined U.K. album sales of nearly three million copies, Georgian-born Katie Melua has quietly become one of the biggest-selling female artists of the decade. Without the media profile of Britney Spears, the powerhouse vocals of Anastacia, or the critical acclaim of Dido, her success has been based purely on old-fashioned songs that have managed to have appeal beyond the usual folk-pop market. Indeed, just like her biggest influence, Eva Cassidy, who appears here on a posthumous cover of "What a Wonderful World," Melua's soothing and jazz-tinged tones found an audience through repeated plays on Terry Wogan's BBC Radio 2 show. So the fact that the majority of The Katie Melua Collection never really moves past first gear shouldn't come as any surprise.