The Castrato is the first book to explore in depth why innumerable boys were castrated for singing between the mid-sixteenth and late-nineteenth centuries. It shows that although the practice formed the foundation of Western classical singing, it was birthed from an unlikely and historically unique set of desires, public and private, aesthetic, economic, and political. In Italy, castration for singing was understood through the lens of Catholic blood sacrifice as expressed in idioms of offering and renunciation and, paradoxically, in satires, verbal abuse, and even the symbolism of the castrato's comic cousin Pulcinella. Sacrifice in Italy also encompassed a logic of reproduction, involving teachers, patrons, colleagues, and relatives. Yet, what lured audiences and composers--from Cavalli and Pergolesi to Handel, Mozart, and Rossini--were the extraordinary capacities of castrato voices, a phenomenon ultimately unsettled by Enlightenment morality. Although the castrati failed to survive, their musicality and vocality persisted long after their literal demise in traditions that extend to bel canto repertories and beyond.