Considering his appeal spanned several generations, fans approach the work of Serge Gainsbourg from a multitude of angles. Initials S.G. is the first widely available, single-disc compilation that treats his career as an artist and influence, not just a hitmaker. And with an entirely new audience of twenty-somethings attracted to his devilish grin and simmering productions, the time was certainly ripe for this “Ultimate Best Of.” Boasting 23 tracks and spanning the years 1958 to 1980, Initials S.G. is the disc necessary for anyone who wants to know why artists from Jarvis Cocker to Beck to David Holmes to Momus have seized on his recordings. Previous collections, especially American releases, were overly focused on single time periods (with all the accumulating dross) and often made little attempt to help listeners decide which era they preferred. It’s all laid out here, ranging from the brisk postwar jazz-pop of 1964′s “Couleur Cafe” to the stoned funk pornography of 1971′s “Ballade de Melody Nelson” — only seven years apart technically, but separated by a vast cultural gulf that could be Johnny Mathis and Johnnie Taylor in comparison. Gainsbourg’s power to fascinate later generations is especially powerful on the spare, funky soundtrack feature “Requiem Pour une C…”; the infamous “Je T’Aime…Moi Non Plus,” a 1969 chart entry featuring the orgasmic vocal caressing of Jane Birkin; and an ace throwaway of yeh-yeh pop called “Bonnie and Clyde,” featuring Brigitte Bardot. (The disc unfortunately brushes over “Lemon Incest,” the source of his wildest controversy, a song on which Gainsbourg crooned with his daughter Charlotte, and lay in bed with her for the video.) The only buyer-beware caution necessary for Initials S.G. is that most purchasers will soon find themselves buying imports of original LP masterpieces like 1971′s Histoire de Melody Nelson or 1969′s Serge Gainsbourg & Jane Birkin. – John Bush