Carmen (Bizet, 1875): Man disregards advice from woman, with grave consequences.
Orfeo ed Euridice (Gluck, 1762): Man disregards advice from deity, with grave consequences.
Der fliegende Holländer (Wagner, 1843): Woman disregards advice from ghost pirate, with grave consequences.

Così fan tutte (Mozart, 1790): The composer does not like his wife.
Fidelio (Beethoven, 1805–14): The composer likes the idea of having a wife, but would settle for a free and just society.
Tristan und Isolde (Wagner, 1865): The composer likes other people’s wives.

La Traviata (Verdi, 1853): All you need is love.
Pagliacci (Leoncavallo, 1892): The tears of a clown, when everyone’s around.
Die Zauberflöte (Mozart, 1791): You say you want a revolution, and your bird can sing.

Rienzi (Wagner, 1840): The composer would like to make some money in Paris.
Tannhäuser (Wagner, 1845): The composer demonstrates that the Twisted Sister/Tipper Gore feud would have had a much larger body count had it occurred in medieval Germany.
Die Meistersinger von Nürnberg (Wagner, 1868): The composer thinks you should know that he read your review and it still stings a bit.
Parsifal (Wagner, 1882): The composer spent a lot of late nights thinking aloud in his dorm room the semester he took Intro to World Religions.

Falstaff (Verdi, 1893): It might actually be possible to improve on Shakespeare.
Roméo et Juliette (Gounod, 1867): But not like this.
Das Liebesverbot (Wagner, 1836): And absolutely not like this.

La nozze di Figaro (Mozart, 1786): Rich people are terrible.
Madama Butterfly (Puccini, 1904): Americans are terrible.
La Bohème (Puccini, 1896): Infectious diseases are terrible.
Das Rheingold (Wagner, 1869): Teutonic deities are terrible.
Guillaume Tell (Rossini, 1829): Habsburgs are terrible.
Die Fledermaus (J. Strauss, 1874): Operetta is terrible.