When This Is Spinal Tap first premiered in 1984, few could have predicted that its deadpan take on rock and roll hubris would become one of the most quoted, beloved, and influential comedies in film history. Forty years later, Rob Reiner and the original trio, Christopher Guest, Michael McKean, and Harry Shearer, have returned to the amplifiers that once went “one louder.” The result, Spinal Tap 2: The End Continues, is a surprisingly tender, frequently hilarious love letter to aging artists, enduring friendship, and the absurd beauty of making noise together long after the world has stopped listening. It could have been a disaster. So many late-stage sequels stumble into the traps of nostalgia or self-parody. But Spinal Tap 2 largely sidesteps those pitfalls by doing something bold: it embraces its own age. This isn’t the swaggering, spandex-clad satire of 1984. This is a story about three men who once believed their music could shake arenas, and who now find meaning in shaking hands,...