libretto

thumb|Cover of a 1921 libretto for Umberto Giordano|Giordano's [[Andrea Chénier]] A libretto (from the Italian word , ) is the text used in, or intended for, an extended musical work such as an opera, operetta, masque, oratorio, cantata or musical. The term libretto is also sometimes used to refer to the story line of a ballet or the texts of major liturgical works, such as the Mass, requiem, or sacred cantata.

The Italian word (, ) is the diminutive of the word libro ("book"). Sometimes other-language equivalents are used for libretti in that language, livret for French works, Textbuch for German and libreto for Spanish. A libretto is distinct from a synopsis or scenario of the plot, in that the libretto contains all the words and stage directions, while a synopsis summarizes the plot. Some ballet historians also use the word libretto to refer to the 15- to 40-page books which were on sale to 19th century ballet audiences in Paris and contained a very detailed description of the ballet's story, scene by scene.