tracks (songs punctuated with sound effects, pillow talk and theatrical sound bites) and titles ("Throb," "The Body That Loves You") that spell out the album's theme, this is Jackson's erotic rite of passage. Collaborations with opera diva Kathleen Battle and Public Enemy's Chuck D hint at the music's allusiveness ­ from MOR balladry to Memphis soul, from house to jazz. In more versatile voice than ever, Jackson perches atop the rhythmic percolations ­