To some people he is known as the Shakespeare of dance — a title that he probably deserves more than anyone else now living. But to his friends and colleagues, he is simply "Mr. B" — George Balanchine, the ageless Russian-born and trained choreographic genius whose zest for living is matched only by his humility and his sense of humor. Balanchine has almost single-handedly transplanted ballet to American soil and made it flourish. What's more, he has played the central role in making New York the dance capital of the world, which it undeniably is today for both classical and modern dance.