The brazen bull was an ancient Sicilian torture device invented by the craftsman Perilaus on the orders of the despot Phalaris of Acragas. It was used to play "music" powered by the cries of the tortured.
Victims were put inside the bull, and a fire was kindled beneath its belly. A set of pipes was affixed to the bull's nostrils. While the person inside was being slowly roasted, his cries were muted by the pipes and supposedly sounded like the lowing of a cow.
Though Phalaris was reputedly a sadist, he claimed that this torture device disgusted even him. He had Perilaus climb inside the bull to demonstrate the "music." Once the craftsman was inside, Phalaris had the fire lit and, after a few minutes of torture, had him pulled from the bull and thrown over a cliff.