"John Cage, composer, painter, and all-round thinker and cultural catalyst, said that if you introduce twenty percent of novelty into any artwork, watch out -- you are going to lose eighty percent of your audience at once. He said you would lose them for fifteen years. Cage was interested in fifteen-year cycles. But he was hopelessly optimistic. The general appreciation, for example, of Western painting has got stuck around Impressionism, and that was 130 years ago, not fifteen years ago."