Literaturoper  Literaturoper ("literature opera", plural “Literaturopern”), a term coined by the German music critic Edgar Istel, describes a genre of opera that emerged during the late 19th century. 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. Although the term is German, it can be applied to any kind of opera, irrespective of style or language. (In that sense it can be regarded as a term rather than a genre as such.) The former, much broader usage of the term “Literaturoper” for opera libretti on the basis of dramas, novels and short stories of undoubted literary renown, which was still common until around 1980, has been made obsolete by recent research on the history of the opera libretto. Since opera libretti have relied on subject matter from the history of literature since the very origin of the genre of opera, a broader usage of the term would cover the entire history of opera, regardless of the underlying libretto structure. According to a seminal publication by Peter Petersen, the term means „a special form of music theater in which the libretto is based on a literary work whose linguistic, semantic and aesthetic structure remains recognizable in the musical-dramatic work as a structural layer.“ The tradition of literaturoper only became established in European opera culture when, with Richard Wagner and the "through-composed dramatic form" he developed, the conventions of verse metrics for the opera libretto had faded. At the same time, the personal union of libretto poet and composer appeared as the new norm of opera production. Especially in the area of the Romance languages, the allitterating verse in Wagner's "Ring des Nibelungen" was perceived as prose text, since the use of allitteration 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. Since the production of literaturopern possessed the potential to make the function of the opera librettist redundant, the genre was first able to assert itself in those opera cultures in which professional libretto-writing had not been able to develop a centuries-long tradition (Russia, Germany). The first examples of this dramaturgical process can be found in the history of French and Russian music in the second half of the 19th century.Early Russian literaturopern include Alexander Dargomyzhsky’s opera " The Stone Guest" (after Alexander Pushkin) and Modest Mussorgsky’s opera fragment "The Marriage" and his " Boris Godunov" (also after Pushkin).