''Un ballo in maschera'' ''(A Masked Ball)'' is yet another opera by Music/GiuseppeVerdi. Originally intended to be based on the assassination of King Gustave III of Sweden, it underwent ExecutiveMeddling due to the censors refusing to let a king get killed onstage. The setting was therefore shifted to Boston in the 1600's and the king demoted to Count Richard of Warwick. For sanity's sake, we will use the Bostonian names, but in the Swedish setting.

King Riccardo of Sweden has a crush on Amelia, the wife of his best friend and secretary Renato. When Renato finds out, he is convinced that his wife is unfaithful, so he must kill the king to preserve his family's honor. You can probably guess [[DownerEnding how it ends]].
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!!Tropes:
%%* AntiVillain: Renato.
* ArtisticLicenseHistory:
** For one thing, the real King Gustave did not have a crush on his secretary's wife. For that matter, [[spoiler: his assassin]] wasn't his secretary, but a captain in his regiment.
** Even in the Bostonian setting, it's important to take into account that in the 1600's, Boston was run by Puritans, who would not have allowed masked balls.
* CrosscastRole: The pageboy Oscar is played by a soprano.
* DiesDifferentlyInAdaptation: The real Gustave III was shot, but the libretto calls for Renato to stab Riccardo: this was part of the censors demands to distance the opera from the real assassination. Many productions restore the historical gunshot, though.
* EvilSoundsDeep: The conspirators Samuel and Tom are basses, and Renato, the AntiVillain, is a baritone.
* IfICantHaveYou: Subverted; Renato threatens to kill Amelia, but when she requests that she see their son one last time, he relents, and resolves to kill Riccardo instead.
* KingIncognito: Riccardo goes to see Ulrica while dressed up as a sailor.
* MistakenForCheating: Renato doesn't know until it's too late that Riccardo and Amelia never actually consummated their love, or that Riccardo was already planning to give her up and send her away with her husband.
%%* MurderTheHypotenuse: [[spoiler: How King Riccardo is killed]].
* PluckyComicRelief: Oscar, the pageboy, whose arias "Volta la terrea" and "Saper vorreste" provide some levity in this tragic opera.
* PropheciesAreAlwaysRight / SelfFulfillingProphecy: Upon meeting the gypsy fortuneteller Ulrica, Riccardo is told that he will die at the hand of his best friend. He doesn't believe her, but because he is in love with Amelia, [[spoiler: he ends up dead at Renato's hand by the end of the opera]].
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