Sting sat in a dressing room at the Brooks Atkinson Theater, playing 'Yankee Doodle' on the jaw harp. "This is my New Sound," he said between twangs, italicizing the last two words with the studied pomposity of a progressive-rock deejay. "Very American, isn't it? Well, I'm a New Yorker now, so it's fitting." It was the week before the opening of the New York previews of "The Threepenny Opera," Berthold Brecht and Kurt Weill's acerbic study of money and morals in Weimar Republic Berlin, and the Brooks Atkinson, shuttered since spring, had been engaged to provide temporary rehearsal quarters...