Art has no obligation to evolve, but it has a powerful incentive to do so. Art that is static, that captures a dead moment, is nothing. It is, at best, nostalgia; at worst, it can be a blight on our sense of who we are, a shame we pack away. Artists who refuse to listen, participate, and change along with the world around them are not being silenced or punished by censorious college sophomores. They are letting obsolescence devour them, voluntarily. Political correctness is just the inexorable turn of the gear. Falling behind is preventable.
