The leader of this class is, of course, Taylor Swift, who’s been pioneering a futuristic form of storytelling: every verse and every public utterance links together an intricate web of “lore,” which brings fans together for puzzle-solving and reinterpretation.

It’s hard to see history when you’re in the middle of it, harder still to distinguish Swift’s impact on the culture from her celebrity, which emits so much light it can be blinding. But something unusual is happening with Swift, without a contemporary precedent. She deploys the most efficient medium of the day—the pop song—to tell her story. Yet... See more