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.
Leonora (opera)
Leonora, ossia L’amore coniugale ("Leonora or Conjugal Love") is an opera (specifically a "dramma semiserio") in two acts by the Italian composer Ferdinando Paer. The libretto, by Giovanni Schmidt, is based on "Léonore ou L’Amour conjugal" (1794) by Jean-Nicolas Bouilly, which was also the source of Beethoven's "Fidelio". Beethoven himself owned a score of Paer's opera and it is believed to have had some influence on his work. "Leonora" was first performed at the Kleines Kurfürstliches Theater, Dresden on 3 October 1804 with the composer's wife singing the title role.