The picture that sized up Mikhail Baryshnikov for his new audience in the West was an Avedon shot that ran in Vogue in October 1974, four months after the dancer defected. He flew straight up from the page, arms outstretched, chest bare, sky behind him—huge. He flew out of the lap of Vogue and into light. The move could have been the trick of a diver or a gymnast, but the body was pure ballet—that immaculate musculature, the privilege in space, those toes. Baryshnikov had chubby cheeks, which was a shock, and big, round, sad, silent-movie eyes, a blue that sighed the word “persecution.” And it turned out he was small, about five feet six inches. So his round cheeks and round muscles and round-as-a-compass pirouettes and tours en l’air made him seem cherubic, a kind of opulent ballet angel. We knew he came from the Kirov, but with his blazing perfection he could just as easily have dropp ...