Pianists: Bird Boy

The odd creature walking onstage at Manhattan's Carnegie Hall looks like one-third each of Woody Allen, Charlie Chaplin and a sparrow. He bobs to the audience, weaves around the piano, pecks the air with his beak, hovers over the piano bench, then alights. "I don't know whether to laugh or cry," mutters an onlooker to her companion. A moment later she knows: when Vladimir Ashkenazy plays, nobody laughs and everybody cries. They cry real tears sometimes, but mostly they cry "Bravo!" and "Encore!"

Regardless of what people have heard about this 28-year-old...