Agricola published Introduction to the Art of Singing in Germany, in 1757, consisting of the 1723 treatise of the Italian singing teacher and castrato, Tosi, to which Agricola added his own running commentary. The Introduction was recognised as invaluable not only for teachers and their pupils but also for advanced singers and professionals. This present edition, translated with introduction and annotations by the celebrated singer Julianne Baird, makes Agricola’s work available for the first time in English. Tosi’s work was the first basic treatise on singing; Agricola, a pupil of J. S. Bach at the court of Frederick the Great, brought Tosi’s work ‘up to date’. His commentaries are so extensive that the Introduction stands on its own as an important document in the history of performance practice.