(Italian, ‘little book’)
Libretto refers to the words that are sung or spoken in musical works for the theater, including operas, operettas, and oratorios. The author of these words is called the librettist.
The term libretto dates to the late 16th century, when the text of musical works began to be printed in small books, or libretti (the proper plural). Audiences used these libretti to follow the performances.
While the term libretto is occasionally applied to the script (and in some cases, the script and lyrics) of contemporary musical theater productions, the terms book (for the spoken words) and lyrics (sung words) are more common, as in, “Book by Jane Doe, lyrics by John Doe.”
I love the music to The Marriage of Figaro, but since the libretto is in Italian, I can’t understand the words.