Like a champion tennis player or a wizened clockmaker, Taylor Swift has been training all her life to be the artisan she is today. A natural inclination toward synthesizing her problems through painful, earnest koans and an ease with uncomplicated melodies made the singer-songwriter a superstar in Nashville’s country-music ecosystem. By 2012, she had teamed up with dance-pop hitmakers Max Martin and Shellback on her fourth album, Red, seizing control of the mainstream pop circuit as a polished, preternaturally gifted love-song architect and a seemingly unflappable public figure, the image of CMA charm with a light dusting of VMA smarm.