Libretto
Text book of an opera.
What it means
The libretto is the text book of an opera, an oratorio, or another stage or vocal work. The word means “little book” and originally designated the printed edition that served the audience for following along. It is written by the librettist, occasionally by the composer themselves. It contains the sung text, the division into acts and scenes, and as a rule information about setting and plot.
Musical use
The libretto is not a mere template but co-determines the musical layout: it fixes where the action is driven forward and where a character lingers, and thereby the distribution of recitative, aria, and ensemble. Metre and stanza structure give the music its frame; regular verse invites closed numbers, free speech rather through-composed scenes. Collaboration between poet and composer varied depending on period and person — sometimes the librettist delivered a finished poem, sometimes the text was reworked according to musical requirements. Many librettos were set to music more than once.
Performance practice
Read the libretto completely before studying your part, and not only your own scenes; references and addresses often arise from other passages. Clarify unfamiliar words and, for works in a foreign language, get a literal translation, not just a summary of content. Watch metre and rhyme, because they support the phrasing. With cut versions, check whether the plot still remains understandable, and clarify cuts early within the ensemble.
Bear in mind that many librettos were set to music more than once and circulated in different versions: check which text version underlies your edition when working with translations or literature. With cuts it must be clarified whether the plot stays understandable; this often concerns precisely the recitatives, which count as dispensable and yet carry the connections. Compare the libretto with the text as set, since composers have often shortened or rearranged verses.
Check whether a translation is provided in the programme booklet, and clarify whether it matches the version performed.