 George Antheil, the self-proclaimed "Bad Boy of Music," was a brash, colorful, young "ultra-modern" American pianist and composer during the roaring  20s, whose works caused fistfights in concert halls and riots in the streets from London to Budapest. His magnum opus, the "Ballet mécanique," for percussion, sound effects, and multiple player pianos, turned Paris on its ear in 1924. But the piece called for technology that didn t exist at the time. It took a forward-thinking music publisher, a music technologist, a modern player-piano manufacturer, and the latest in computer technology before the piece was heard the way the composer wanted it-75 years after it was written.