Handwringing about “what is literature?” seems inevitable after the announcement that a rock star has taken the global writing community’s biggest award. But no great existential crisis is needed. The Nobel Committee could have decided that with this prize it wanted to expand the definition of “literature” to include recorded music, a hugely influential and relatively young art form that doesn’t have an award of Nobel-like prestige dedicated to it. But it seems to have declined to do so.