There's no denying Niccolò Paganini was a virtuoso -- in his heyday, this violinist was an international rock star, wowing crowds across Europe with his rollicking, frenetic performances. He was, in fact, so good that people were at a loss to explain exactly how he got so talented. As the years went on, people started claiming his musical gifts were the result of an infernal pact, and that Paganini had made a deal with the Devil.