On the semi-sequel to ''Livin' on a Prayer,'' Jon Bon Jovi declares ''It's My Life.'' While it's worrisome that the 38-year-old can earnestly deliver an anthem that sounds as if it sprang from a high schooler stuck in detention, it's tough to deny the song's captivating chorus. But if the Jersey rockers haven't matured much, it hardly matters. Crush for all its sappy ballads and surburban pop fairy tales is classic Bon Jovi. And that's not an oxymoron. B

