Pier Francesco Tosi (c. 1653 – 1732) was a castrato singer, composer, and writer on music. His Opinoni de' cantori antichi e moderni... was the first full-length treatise on singing and provides a unique glimpse into the technical and social aspects of Baroque vocal music.Tosi was born in Cesena, Italy in 1653 or 1654. There is a disagreement among sources whether he was the son of composer Giuseppe Felice Tosi. He was castrated before puberty to preserve his high voice. While it is not known where he received his rudimentary music training, he sang at a church in Rome from 1676 to 1677 and at the Milan cathedral from 1681 until 1685, when he was dismissed for “misconduct.” Thereafter, he made his one recorded appearance in opera at Reggio nell’Emilia in 1687 (in Varischino’s Odoacre) and was based for a time in Genoa. In 1693 Tosi relocated to London where he took on singing students and sang in weekly public concerts. In 1701 he entered into the service of Austrian Emperor Joseph I and Johann Wilhelm, Elector Palatine, whom he served as a musical and diplomatic agent, traveling extensively until 1723. In 1724 he returned to a London ablaze with the works of Handel, where he again taught and was a founding member of the Academy of Ancient Music. He took holy orders sometime before his death in Faenza, Italy in 1732. In addition to being a well-known soprano (of the cantabile style, singing mostly chamber music) and voice teacher, Tosi was a composer of several arias and cantatas. Less