A sonority unique to the Baroque period was the voice of the castrato, an adult male soprano or mezzo-soprano who, in order to accommodate the papal proscription of women singing in church, was castrated before puberty. This barbaric practice (though officially condemned by the church) led to the advent of a generation of operatic superstars enthusiastically acclaimed in Italy, Germany, and England. Italian castrati often sang the principal male roles in Italian opera seria (serious opera) and were imported to England by Handel’s Royal Academy of Music, an aristocratic joint-venture opera company founded in 1719. However, throughout his career, Handel freely interchanged female singers in male costumes for castrati, especially when the high-priced virtuosos were in short supply. Modern performances replace the extinct castrati either with female singers en travesti or by countertenors, men who have raised the technique of falsetto singing to virtuosic heights.

The opera seria Giustino was written for the 1736-37 opera season, by which time Handel had been ousted from the King’s Theatre to Covent Garden by a rival opera company headed by the Prince of Wales. An alto castrato, Domenico Annibali, sang the title role of an historical figure, the illiterate Bulgarian peasant Justin I (450-527) who was called to become commander of the Imperial Guard and eventually became emperor of Byzantium. Although the circumstances of the plot are fictional, Giustino’s opening aria, “Se parla nel mio cor,” is a wholly plausible reflection of a ploughman who is called to military service. Playing in the trumpets’ customary key of D major, the strings play fanfare figures in the snappy rhythm of the corta (short-short-long or its reverse), echoed by Giustino on the words “intrepido valor.”