Initially settling in Rome, Sacchini spent several years composing "opere buffe" for the Teatro Valle. These works made him famous throughout Europe. One of the most notable of them – it has been revived and recorded in modern times – was the two-act intermezzo "La contadina in corte" (1765). In 1768, Sacchini moved to Venice, having accepted the temporary post of director of the Conservatorio dell'Ospedale dei Poveri Derelitti (the "Ospedaletto"), offered by his predecessor in the job Tommaso Traetta, who had been Sacchini's friend since their studies together in Naples and who was now leaving Venice to work at the court of Saint Petersburg. In Venice, Sacchini soon made a name for himself as a singing master (his pupils included Nancy Storace and, possibly, Adriana Gabrielli, who, under the name Adriana Ferrarese del Bene was subsequently to go down in history as the first singer to play Mozart's Fiordiligi). While continuing to pursue his career as an opera composer, he also spent time writing sacred pieces (oratorios, masses, hymns, motets) for the Conservatorio and various Venetian churches, as his contract required.