text: The year 1752 brought another major commission to Gluck, when he was asked to set Metastasio's La clemenza di Tito (the specific libretto was the composer's choice) for the name day celebrations of King Charles VII of Naples. The opera was performed on 4 November at the Teatro di San Carlo, and the world-famous castrato Caffarelli took the role of Sextus. For Caffarelli Gluck composed the famous, but notoriously difficult, aria "Se mai senti spirarti sul volto", which provoked admiration and vituperation in equally large measures. Gluck later reworked this aria for his Iphigénie en Tauride. According to one account, the Neapolitan composer Francesco Durante claimed that his fellow composers "should have been proud to have conceived and written [the aria]". Durante simultaneously declined to comment whether or not it was within the boundaries of the accepted compositional rules of the time.
  Vienna
  Gluck finally settled in Vienna, where he became Kapellmeister invited by Prince Joseph of Saxe-Hildburghausen. He wrote Le cinesi for a festival in 1754 and La danza for the eighth birthday of the future Emperor Leopold II the following year. After his opera Antigono was performed in Rome in February 1756, Gluck was made a Knight of the Golden Spur by Pope Benedict XIV. From that time on, Gluck used the title "Ritter von Gluck" or "Chevalier de Gluck".
  Gluck turned his back on Italian opera seria and began to write opéra comiques. In 1761 Gluck produced the groundbreaking ballet-pantomime Don Juan in collaboration with the choreographer Gasparo Angiolini; the more radical Jean-Georges Noverre was involved for the first time? The climax of Gluck's opéra comique writing was La rencontre imprévue (1764). By that time, Gluck created musical drama, based on Greek tragedy, with more compassion, influencing the latest style Sturm und Drang.