Fosca is an opera seria in four acts by Brazilian composer Antônio Carlos Gomes to an Italian-language libretto by Antonio Ghislanzoni based on 's 1869 novel La festa delle Marie.
The opera premiered at La Scala in Milan on February 16, 1873. It was a failure because of a dispute between lovers of bel canto and supporters of Wagnerian music-drama. Gomes revised it in 1877, and the premiere of the new version (this time described as a melodramma) on February 7, 1878, also at La Scala, was a success.
Since then, performances of the opera, mostly in Brazil, have been rare. The most recent productions, in both cases of the revised version, were given at the Teatro Amazonas, Manaus, in May 1998, and by Wexford Festival Opera in October of the same year. In 2016, Theatro Municipal de São Paulo has made a new production of the opera, staged in December.
The pirates' lair near Piran
The pirates ask Gajolo about their next raid. He is planning a kidnapping of brides who are participating in the "Feast of the Marys" at San Pietro in Venice. Cambro arrives to report that Michele Giotta, father of the pirates' prisoner, Paolo, is offering a reward for his son's return. Fosca, who loves Paolo, suggests double-crossing Giotta and claiming the money without releasing Paolo. The pirates reject this dishonourable plan. Gajolo asks Cambro to watch Fosca, and the pirates depart. Paolo, thinking he is to be executed, is brought out of his cell by Fosca. She confesses her love for him, but he rejects her: he is in love with Delia, to whom he is betrothed. Gajolo reappears with Giotta, who has paid Paolo's ransom, and, to Fosca's horror, father and son leave for Venice. Cambro asks Fosca what his reward might be if he can deliver Delia to her. She replies "I will marry you".