
1) Czech-language opera 2) German-language opera 3) One-act opera 4) Opera by Franz Schreker
Found on
https://www.crosswordclues.com/clue/flammen

Flammen (Flames) is a one-act opera by Franz Schreker, on a libretto by Dora Leen, pseudonym of Dora Pollak (b. 23 October 1880, d. Auschwitz c.1942). ==Composition history== Dora Pollak`s father, the well-known Viennese doctor Siegmund Pollak, was personal physician to Ferdinand von Saar, an important Austrian literary figure and also Schreker`.....
Found on
http://en.wikipedia.org/wiki/Flammen
No exact match found.