Droit du seigneur
In Mozart's "The Marriage of Figaro", which premiered in 1786 with a libretto by Lorenzo Da Ponte, the comic plot revolves around the successful efforts of the young bride and groom, Figaro and Susanna, to block the efforts of the unfaithful Count Almaviva to seduce Susanna. To achieve his aim, the frustrated Count threatens to reinstitute "droit du seigneur". It was based on a play by Pierre Beaumarchais.
Antonio Salieri
Upon returning to Vienna following his success in Paris, Salieri met and befriended Lorenzo Da Ponte and had his first professional encounters with Mozart. Da Ponte wrote his first opera libretto for Salieri, "Il ricco d'un giorno" (A rich man for a day) in 1784, which was not a success. Salieri next turned to Giambattista Casti as a librettist; a more successful set of collaboration flowed from this pairing. In the meantime Da Ponte began working with Mozart on "Le nozze di Figaro" ("The Marriage of Figaro"). In 1785 Salieri produced one of his greatest works with the text by Casti, "La grotta di Trofonio" (The cave of Trophonius), the first opera buffa published in full score by Artaria. Shortly after this success Joseph II had Mozart and Salieri each contribute a one-act opera and/or singspiel for production at a banquet in 1786. Salieri collaborated with Casti to produce a parody of the relationship between poet and composer in "Prima la musica e poi le parole" ('First the music and then the words). This short work also highlighted the typical backstage antics of two high flown sopranos. Salieri then returned to Paris for the premiere of his tragédie lyrique "Les Horaces" (The Horatii), which proved a failure, which was more than made up for with his next Parisian opera "Tarare", with a libretto by Beaumarchais. This was intended to be the "" of reform opera, a completely new synthesis of poetry and music that was an 18th-century anticipation of the ideals of Richard Wagner. Salieri also created a sacred cantata "Le Jugement dernier" (The Last Judgement). The success of his opera "Tarare" was such that it was soon translated into Italian at Joseph II's behest by Lorenzo Da Ponte as "Axur, re d'Ormus" (Axur, king of Hormuz) and staged at the royal wedding of Franz II in 1788.