I Vespri Siciliani
ACT I. In Palermo, French troops carouse in the square as Sicilians hostilely observe them ("A te, ciel natio"). Duchess Elena mourns her brother Frederick of Austria, executed by the French for treason. She is approached by a drunken French officer, who commands her to sing a song; when she does so, it is a metaphorical one about a storm-tossed ship inciting the Sicilians to cast off their fears, trust in God and rise against their oppressors ("In alto mare è battuto"). This riles up the populace to attack just as Monforte, the French governor, appears, dispersing them. A young patriot, Arrigo, is released by his guards and tells Elena he has been acquitted of charges of treason, though he still detests Monforte. When she leaves, Monforte asks the young man his name and history; despite his defiant answers about his dead mother and unknown father, Monforte offers the Sicilian fame and fortune in the service of France. Arrigo indignantly declines, whereupon the ruler warns him to avoid the rebel Elena. But Arrigo enters her palace.
ACT II. Outside the city, the patriot leader Procida secretly returns from exile and greets his homeland ("O tu, Palermo") while awaiting his followers. When Elena and Arrigo arrive, he tells them Spanish support is on its way, provided all of Sicily rises against the French. He departs, emphasizing his reliance on Arrigo. The latter confesses his love for Elena, who promises him her hand if he will avenge her brother's death ("Ah, da tue luci angeliche"). A messenger comes from Monforte with an invitation for Arrigo to attend a ball; when he refuses, soldiers lead him away. Returning, Procida is struck by the sight of young couples coming to celebrate their engagement. Using this chance to arouse popular feeling, he suggests to the French soldiers that they abduct some of the girls. The Sicilian men are infuriated and several wounded in the scuffle that follows. Sounds of carefree Frenchmen and their ladies singing a barcarole ("Del piacer s'avanza l'ora!") en route to the ball further enrage the Sicilians, who swear vengeance.
ACT III. Alone in his study, Monforte reflects that he has everything he wants except the love of his long-lost son, whom he has discovered to be Arrigo ("In braccio alle dovizie"). The latter is shown in, and Monforte tells him the truth, hoping to favor him. But the discovery horrifies Arrigo, who sees it as a further barrier between himself and Elena. He condemns his father for the wrong he did to his mother, but Monforte appeals -in vain- for his love, while Arrigo despairs at this new situation ("Quando al mio sen").
In the ballroom, the guests include some wearing green ribbons, which mark them as conspirators against Monforte's life. Procida fastens one on Arrigo, who is torn between his filial instinct and loyalty to his friends. He warns Monforte, explaining the meaning of the ribbons. As Monforte tears the ribbon off Arrigo, the conspirators, headed by Elena, surround Monforte and attempt to assassinate him. Evading them, he orders the arrest of all but Arrigo, whom he proclaims his savior. The Sicilians vow to avenge Arrigo's treachery ("Colpo orrendo, inaspettato!").
ACT IV. The unhappy Arrigo has obtained a pass from Monforte to visit the prisoners. His heart is with them, but he questions whether they will listen to his explanation ("Voi per me qui gemete"). Elena is ushered in and expresses disgust for him, but by revealing that Monforte is his father, Arrigo shakes her determination. Declaring his free to rejoin the conspiracy, she confesses she has suffered in hating him ("Arrigo! ah, parli a un core"). The lovers vow eternal fidelity ("E dolce raggio, celeste dono"). Procida, led in by soldiers, whispers to Elena that a ship from Aragon with weapons lies off the port. Noticing Arrigo, he doubts the young man's repentance and suspects more treachery. Monforte arrives and orders execution of the prisoners, but Arrigo pleads for their lives, saying he will die with them. The ruler tells him to remember he is his son, a revelation that throws Procida into despair. Arrigo again begs for clemency, but Monforte's price is that he recognize him as his father. Again refusing, Arrigo is weakened by the sight of the execution block and sound of chanting monks. Finally he agrees, and Monforte stops the execution, announcing the immediate wedding of Elena and his son as a sign of reconciliation. Procida whispers to the hesitant Elena that she must comply for the sake of her brother, while Monforte announces a pardon to the happy populace. The two sides come together ("Oh, mia sorpresa, oh giubilo").
ACT V. Before the Church of Santo Spirito, a crowd celebrates the wedding. Elena approaches in her bridal attire and sings of her happiness. ("Mercè, dilette amiche"). Arrigo joins her for a moment, after which Procida comes to tell Elena that vengeance is near: when bells ring for the marriage ceremony, the Sicilian populace will attack the unarmed French. She is horrified, but Procida dares her to denounce him now, which she cannot do. Instead, to avert the signal, she refuses to proceed with the marriage. Arrigo is shattered and tells Monforte, who brushes aside her objections and, placing her hand in Arrigo's, orders the bells rung. The Sicilians pour in and massacre the French.
-- courtesy of Opera News