A male singer who was castrated during boyhood to preserve the soprano or alto vocal register, prominent in 17th- and early 18th-century opera. This practice was sanctioned by the Vatican because women were not permitted to sing in the church. Castrati were popular in Italian churches in the 17th and 18th centuries and became important in Italian operas; many roles were written especially for them. nowadays, roles originally intended for castrati are sung by women