Mozart composed "Don Giovanni" for the Italian Opera at Prague, which had been saved from ruin in the season 1786-1787 by the phenomenal success of "Le Nozze di Figaro." He chose the subject and commissioned Lorenzo da Ponte, then official poet to the imperial theatres of Austria, to write the book of words. In doing so, the latter made free use of a version of the same story made by an Italian theatrical poet named Bertati, and Dr. Chrysander (who in 1886 gave me a copy of this libretto, which Mozart's biographer, Otto Jahn, had not succeeded in finding, despite diligent search) has pointed out that Mozart also took as a model some of the music to which the composer Gazzaniga had set it. The title of the opera by Bertati and Gazzaniga was "Il Convitato di Pietra." It had been brought forward with great success in Venice and won wide vogue in Italy before Mozart hit upon it. It lived many years after Mozart brought out his opera, and, indeed, was performed in London twenty-three years before Mozart's opera got a hearing. It is doubtful, however, if the London representation did justice to the work. Da Ponte was poet to the opera there when "Il Convitato" was chosen for performance, and it fell to him to prepare the book to suit the taste of the English people. He tried to persuade the management to give Mozart's opera instead, and, failing in that, had the malicious satisfaction of helping to turn the work of Bertati and Gazzaniga into a sort of literary and musical pasticcio, inserting portions of his own paraphrase of Bertati's book in place of the original scenes and preparing occasion for the insertion of musical pieces by Sarti, Frederici, and Guglielmi.