Relationship of composer and librettist
Libretti for operas, oratorios and cantatas in the 17th and 18th centuries generally were written by someone other than the composer, often a well-known poet. Metastasio (1698–1782) (real name Pietro Trapassi) was one of the most highly regarded librettists in Europe. His libretti were set many times by many different composers. Another noted 18th-century librettist was Lorenzo Da Ponte, who wrote the libretti for three of Mozart's greatest operas, as well as for many other composers.
Eugène Scribe was one of the most prolific librettists of the 19th century, providing the words for works by Meyerbeer (with whom he had a lasting collaboration), Auber, Bellini, Donizetti, Rossini and Verdi. The French writers' duo Henri Meilhac and Ludovic Halévy wrote a large number of opera and operetta libretti for the likes of Jacques Offenbach, Jules Massenet and Georges Bizet. Arrigo Boito, who wrote libretti for, among others, Giuseppe Verdi and Amilcare Ponchielli, also composed two operas of his own.
The libretto is not always written before the music. Some composers, such as Mikhail Glinka, Alexander Serov, Rimsky-Korsakov, Puccini and Mascagni wrote passages of music without text and subsequently had the librettist add words to the vocal melody lines. (This has often been the case with American popular song and musicals in the 20th century, as with Richard Rodgers and Lorenz Hart's collaboration, although with the later team of Rodgers and Hammerstein the lyrics were generally written first.)
Some composers wrote their own libretti. Richard Wagner is perhaps most famous in this regard, with his transformations of Germanic legends and events into epic subjects for his operas and music dramas. Hector Berlioz, too, wrote the libretti for two of his best-known works, La Damnation de Faust and Les Troyens. Alban Berg adapted Georg Büchner's play Woyzeck for the libretto of Wozzeck.
Pages from an 1859 libretto for Ernani
, with the original Italian lyrics, English translation and musical notation for one of the arias.
Sometimes the libretto is written in close collaboration with the composer; this can involve adaptation, as was the case with Rimsky-Korsakov and his librettist Bel'sky, or an entirely original work. In the case of musicals, the music, the lyrics and the "book" (i.e., the spoken dialogue and the stage directions) may each have their own author. Thus, a musical such as Fiddler on the Roof has a composer (Jerry Bock), a lyricist (Sheldon Harnick) and the writer of the "book" (Joseph Stein). In rare cases, the composer writes everything except the dance arrangements - music, lyrics and libretto, as Lionel Bart did for Oliver!.
Other matters in the process of developing a libretto parallel those of spoken dramas for stage or screen. There are the preliminary steps of selecting or suggesting a subject and developing a sketch of the action in the form of a scenario, as well as revisions that might come about when the work is in production, as with out-of-town tryouts for Broadway musicals, or changes made for a specific local audience. A famous case of the latter is Wagner's 1861 revision of the original 1845 Dresden version of his opera Tannhäuser for Paris.