castrato

In music, a high male voice of unusual brilliance and power achieved by castration before puberty, regarded as the ideal timbre for heroic roles in opera by composers from Monteverdi to Wagner. Castrati were mainly, but not exclusively, active in 17th- and 18th-century Italy, where they sang soprano and alto parts in theatres and churches. Recordings preserve the voice of Alessandro Moreschi (1858–1922), the last male soprano of the Sistine Chapel.

Castration interrupts the normal growth of the vocal folds in the larynx at puberty, preventing the mature male voice from descending in pitch, while allowing vocal prowess to benefit from adult growth in all other respects.