Fame often does an artist little good. Quite apart from the moral temptations, there is the danger of sticking with what works, closing oneself off to new ideas, refusing new challenges, becoming a brand. In Michelangelo’s case, fame’s ill effects, limited in his lifetime, in the long run turned disastrous. To be sure, Michelangelo never let success freeze his creativity; he remained brilliantly creative down to the end of his long life. But once he had achieved his place in the world of Renaissance art, he confined his creative energies within rather strict guiderails. He stopped taking certain risks. After some youthful experiments, he showed little stylistic development, and almost none in his last fifty years (he lived to eighty-eight). He clung to the techniques he had learned in his youth. Unlike his older contemporary Leonardo da Vinci, he was no experimenter when it came to artistic media. His longtime collaborator Sebastiano del Piombo, trained in the latest Venetian techniques of oil painting, tried to push him into experimenting with the new medium. A fascinating exhibition earlier this year at London’s National Gallery, “Michelangelo & Sebastiano,” traced the interaction of their partnership over two decades. Michelangelo clearly respected his younger partner’s skills in oil but never tried to master the medium himself, remaining wedded to the traditional Florentine techniques of fresco and painting on panel with egg tempera. The lines of influence in their collaboration went in only one direction. When in 1536 Sebastiano tried to nudge him