castrato, male soprano or contralto voice of great range, flexibility, and power, produced as a result of castration before puberty. The castrato voice was introduced in the 16th century, when women were banned from church choirs and the stage. It reached its greatest prominence in 17th- and 18th-century opera. The practice of castration, illegal and inhumane, produced an adult voice of extraordinary power attributable to the greater lung capacity and physical bulk of the adult male.
The unique tone quality of the voice, coupled with the ability of the intensively trained singers to execute extremely difficult florid vocal passages, made the castrati the rage of opera audiences and contributed to the spread of Italian opera. In 18th-century opera the majority of male singers were castrati. The most famous of the Italian castrati was Carlo Broschi, known as Farinelli.