When the World Stopped to ListenBy: Stuart Isacoff April 1958: The Soviets were leading the space race, the Iron Curtain was at its heaviest, and the Tchaikovsky International Piano Competition in Moscow seemed certain to crown a hometown champion. But as the worlds finest young pianists descended on the Russian capital, an unlikely favorite emerged: Van Cliburn, a polite, lanky Texan whose passionate virtuosity captured the hearts of the Russian peopleand thawed Cold War tensions