Meghan Trainor helped make booty big in 2014 with her body-positive smash "All About That Bass." While the 21-year-old singer rocks more sass and self-empowerment on her full-length major-label debut (which, confusingly, shares a name with the four-song EP she released in September), she's also charmingly old-fashioned. Doo-wop is Trainor's thing, from the girl-group bounce of "Dear Future Husband" to the finger-snapping balladry of "Like I'm Gonna Lose You," where John Legend plays Marvin to her Tammi. To her credit, Trainor – whose torch-y, tangy vocals can suggest a scrubbed-up Amy Winehouse – co-wrote every tune. Baby's got her own back.