https://en.wikipedia.org/wiki/Libretto
WebA libretto (Italian for "booklet") 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 text of major liturgical works, such as the Mass, requiem and sacred cantata, or the story line of a ballet.. Libretto (pronounced ; plural libretti), from …