From Taylor Swift to Tanya Tucker, country music has a rich history of child stars. Maddox Batson , at just 16, is the latest, drawing comparisons to young Justin Bieber with his songs about middle-school crushes and country living. He and Bieber also share the same vocal coach he tells Rolling Stone ’s Nashville Now podcast . “Mama Jan. She’s absolutely wonderful… She knows how to handle young male voices,” Batson says. “Through puberty and how your voice will change and stuff, she has that