The prologue begins with Carlo Broschi, the famous castrato Farinelli, reminiscing about his childhood as a singer in the church choir. A newly castrated boy runs in and warns Carlo that his voice will result in death, then kills himself. Carlo is traumatized and refuses to sing a composition by his older brother Riccardo for his voice teacher, Nicola Porpora. He cries and runs to his father, who comforts him, but extracts a promise that he will never refuse his voice to his brother again.