Ezio, the ‘pasticcio’ opera which opened the Italian opera season at the King’s Theatre, Haymarket on 24 November 1764, was based on one of Metastasio’s most popular and well-known texts. The very nature of ‘pasticcio’ operas meant that only the basic skeleton (specifically the recitatives) of the original libretto was retained, but the inclusion of arias whose texts originally belonged in a different setting and context was not as great a problem as it might initially seem, given how generalised and stereotypical many of these aria texts were.
Giovanni Manzuoli, the celebrated castrato who was singing the title role, was a particular admirer of the Venetian composer Giovanni Battista Pescetti, and it was presumably his decision to include in Ezio an aria by Pescetti for him to sing. Born in the first decade of the eighteenth century, Pescetti had actually come to London in 1736, replacing Nicola Porpora as director of the Opera of the Nobility, the company which had been set up in direct competition to Handel (it was Porpora, incidentally, who had first set Metastasio’s Ezio, in 1728, and Handel premièred his own setting of the libretto in London four years later). He enjoyed some success in London, and Charles Burney wrote that 'though he never had much fire or fertility of invention [he] was a very elegant and judicious writer for the voice'. After his company was forced to move to a smaller theatre and shrink its budgets he was reduced to arranging ‘pasticcio’ operas, and around 1745 he returned to Venice, where he died in 1766.
His aria 'Caro mio bene, addio' was sung by Manzuoli in Act 2, scene 5 of Ezio, and the young Mozart was certainly familiar with the aria—his father brought a handwritten copy of it back home to Salzburg, where it remained in his library. The Roman Emperor Valentinian III has wrongly accused his illustrious general Ezio (conqueror of Attila the Hun) of attempting to assassinate him, and has now discovered that his own wife Fulvia and Ezio are in love with each other. Valentinian furiously denounces Fulvia, and orders Ezio to be dragged off to suffer his malicious vengeance. Before being led away, Ezio bids an anguished but stoical farewell to his beloved Fulvia.
from notes by Ian Page © 2018