"I want all hell to break loose!" bellowed Impresario Leon Leonidoff one morning last week in the rehearsal gloom of Manhattan's cavernous Radio City Music Hall. By the time the Russian accent had floated up to the stage, about half a block away, things had begun to pop.
A gaudy carousel spun itself down onto the stage floor and suddenly, over the combined voices of 30 singers, a 75-piece orchestra and the world's biggest organ, brilliant explosions banged across the stage sky. For two minutes, while Leonidoff flailed his arms like a man rooting home a winning horse, the sky erupted rockets,...