It was all there at the very beginning for Taylor Swift: romance, nostalgia and the occasional popping of shiny bubbles of emotion, all within the pristine economical package of a pop-country song. She was 16.

She has never stopped chasing that initial Nashville impulse — a four-ish-minute distillation of the biggest feelings imaginable, threaded through a melody that won’t leave you alone. Sometimes she brings country phrasings to electro-pop, or pop rigor to indie rock; she might let her rhymes and verses go shaggy or bring a bridge back like a chorus. Such are the perks of having mastered the form early, while amassing the cultural capital to remake pop in her image.

Pop stars are not supposed to last this long or create this much. The Beatles’ entire creative output happened, essentially, in eight years. But Swift’s durability — 12 studio albums and hundreds of songs over two decades — has given us an unprecedented combination of musical auteurism and commercial success.

Her later work often explores the tension between the two. She has a campy kiss-off register for tart bon mots — “Lights, camera, bitch, smile / Even when you wanna die,” she chirps on the fake-bubbly “I Can Do It With a Broken Heart.” But on the dream-pop opus “Mirrorball,” it’s all earnest reflection from the top of the mountain: “I can change everything about me to fit in.”

Swift’s latest run of dominance, the stretch that has given her two more Grammys for album of the year (and four in total, a record), began with that surprise pandemic one-two flutter of “Folklore” and its sister album “Evermore.” Simultaneously, Swift was painstakingly recreating four of her earlier albums to own them outright. Collective fervor around the “Taylor’s Version” albums sent a 10-minute director’s cut rendition of a nearly decade-old breakup ballad, “All Too Well,” to No. 1 on the Billboard chart in 2021, simply because so many listeners wanted to hear even more of a track that made them feel bruised, abandoned and devastated.

Swift has done as much as anyone in modern popular music history to advance the idea of the song — its construction and impact, its tensions and limitations — as an important art form. But she has also done it while foregrounding the agency and emotional lives of young women, and as a result has become probably the most pored-over writer — or at least up there with J.K. Rowling and the pope — of the 21st century in any medium. — Joe Coscarelli