This is the decade America's common culture died. Cultural taste, affinity, and identity is shattered into a thousand distinct shards. This “tribalization” has become an obsession among social elites, whose economic model for maintaining their global dominance has been thrown into doubt. But only now are the fuller consequences of the rise of the multiculture rearing their ugly heads. As manufactured mainstream fare fades, Americans are right to begin to wonder whether any popular culture as we know it, a vibrant social sphere full of entertainers and highly engaged audiences, is going to replace what is lost. The same digital technology that empowered us to consume what we wanted, when we wanted it, is now sharply discouraging us from producing what we want, even at times and places of our choosing. The world of digital...