Finally, Cope’s program could divine what made Bach sound like Bach and create music in that style. It broke rules just as Bach had broken them, and made the result sound musical. It was as if the software had somehow captured Bach’s spirit — and it performed just as well in producing new Mozart compositions and Shakespeare sonnets. One afternoon, a few years after he’d begun work on Emmy, Cope clicked a button and went out for a sandwich, and she spit out 5,000 beautiful, artificial Bach chorales, work that would’ve taken him several lifetimes to produce by hand.