Sarrasine

A castrato (plural: castrati) is a male singer who has been castrated—either through the removal of the testicles or through surgery on the connective ducts in the testes—prior to the onset of puberty, thus preventing his voice from dropping and allowing him to sing in the soprano register. Castrati first came to prominence as church singers in the mid-16th century because women—who comprise the overwhelming majority of natural sopranos—were forbidden from singing in many religious settings. This was particularly true in regions of modern Italy, where the advent and popularization of Italian opera in the 17th century opened a new avenue of employment for castrati in secular entertainment. Officially, castration for any reason but medical necessity had been illegal since the late 16th century, but the ban was essentially unenforceable since involved parties could simply lie about the methods and motivations for the operation. 

The best castrati could achieve considerable fame and fortune. Castrato voices were frequently described by contemporaries as having a unique and highly appealing tone particularly suited to the ornate style of Baroque compositions, as well as a power and expressivity ideal for operatic performances. Parts for castrato singers were therefore commonly written into major operas of the era, with their popularity reaching its zenith between the late 17th and early 18th centuries.