Beginning in 1766 Gassmann introduced Salieri to the daily chamber music performances held during Emperor Joseph II's evening meal. Salieri quickly impressed the Emperor, and Gassmann was instructed to bring his pupil as often as he wished. This was the beginning of a relationship between monarch and musician that lasted until Joseph's death in 1790. Salieri met Pietro Antonio Domenico Trapassi, better known as Metastasio, and Christoph Willibald Gluck during this period at the Sunday morning salons held at the home of the Martinez family. Metastasio had an apartment there and participated in the weekly gatherings. Over the next several years Metastasio gave Salieri informal instruction in prosody and the declamation of Italian poetry, and Gluck became an informal advisor, friend and confidante. It was toward the end of this extended period of study that Gassmann was called away on a new opera commission and a gap in the theater's program allowed for Salieri to make his debut as a composer of a completely original "opera buffa". Salieri's first full opera was composed during the winter and carnival season of 1770; "Le donne letterate" and was based on Molière's "Les Femmes Savantes" ("The Learned Ladies") with a libretto by , a dancer in the court ballet and a brother of the composer Luigi Boccherini. The modest success of this opera launched Salieri's 34-year operatic career as a composer of over 35 original dramas.