In the six busy years since Meghan Trainor released “All About That Bass,” the winking doo-wop throwback that made her a viral sensation, the Grammy-winning pop star dropped two albums, toured the world, judged TV talent shows, and collaborated with Kaskade and CNCO. But her biggest strides, she says, have come in her relationship with herself. The singer’s panoramic and upbeat third album, aptly titled TREAT MYSELF, honors her commitment to making music for herself rather than bending to others, and is easily her most confident work to date. She spans a broad range of styles and influences—from tender, gospel-inflected balladry (“Babygirl”) to slick R&B with “Truffle Butter”-esque synths ("Nice to Meet Ya" featuring Nicki Minaj)—but her sweet spot is the glossy R&B-pop that shaped her youth.