When an existing play for the legitimate theatre is set to music without major changes and without the intervention of a librettist, a Literaturoper is the result.
Especially in the area of the Romance languages, the alliterating verse in Wagner's Ring des Nibelungen was perceived as prose text, since the use of alliteration as basis for the poetry in the Ancient Germanic languages had always been alien the syllable-counting verse systems in the French, Italian, Spanish and Portuguese poetic tradition.
[6] Since the Italian tradition of operatic verse proved to be particularly resistant to the introduction of prose libretti, the first Italian literaturopern were created on the basis of Gabriele d'Annunzio’s verse dramas (Alberto Franchetti, La figlia di Iorio (1906), Pietro Mascagni, Parisina (1913), Riccardo Zandonai, Francesca da Rimini (1914), Ildebrando Pizzetti, Fedra (1915).
[7] The first composers to directly set plays include Charles Gounod,[8] Pietro Mascagni, Claude Debussy, Richard Strauss and Alban Berg.
After the Second World War, the genre flourished, especially in Germany, and composers often resorted to setting plays from previous centuries or from Greek Antiquity.