Witnessing the recent imperial progress of Taylor Swift’s Eras Tour, it occurred to me how impossible it is to imagine her ever shedding her current incarnation as world-bestriding, bronze-thighed musical potentate. But of course, she will. The time will come when the hits will dry up and new sorts of eras will beckon: the ‘disappointing sales’ era, the ‘desperate collaboration with younger artists’ era and, ultimately, the ‘Las Vegas residency’ era.