Question: What genre are both Euridice and Der Kaiser von Atlantis?
Context: The Emperor of Austria (German: "Kaiser von Österreich") was a hereditary imperial title and position proclaimed in 1804 by Holy Roman Emperor Francis II, a member of the House of Habsburg-Lorraine, and continually held by him and his heirs until Charles I relinquished power in 1918.  The emperors retained the title of Archduke of Austria.  The wives of the emperors bore the title of empress, while other members of the family bore the title archduke or archduchess. Whittaker "Whit" Cunliffe (15 December 1875 in Haslingden – 1 May 1966) was an English comic singer known for the outfits worn during his stage performances and his World War I song "Hoch, Hoch Der Kaiser" and other songs including "What Does it Matter to Me? " (1906) and "A Different Girl Again".  Cunliffe was described as being a bit of a dandy. Heinrich Claß (February 29, 1868, Alzey – April 16, 1953, Jena) was a German right-wing politician and president of the Pan-German League from 1908 to 1939.  He is commonly known for his books about far-right policy, written under the pseudonym "Daniel Frymann" or "Einhart".  The most famous of these was his 1912 book "Wenn ich der Kaiser wär' " (If I were the emperor), in which he agitates for imperialism, Pan-Germanism and Antisemitism. The Kaiser of California, better known as "The Emperor of California" (German "Der Kaiser von Kalifornien"), is a 1936 film that has the distinction of being the first western film made in Nazi Germany.  Some exterior scenes were even shot on location in the United States at Sedona, Arizona, the Grand Canyon and at Death Valley in California. Camillo Bregant (24 July 1879 in Trieste, coastal land – 21 February 1956 in Arnfels, Leibnitz District Southern Styria) was a Major General, a colonel of the former 5th Styrian, Carinthian and Carniolan Dragoons "Nicholas I Emperor of Russia's Own" "(Steirisch-Kärntnerisch-Krainerisches Dragoner-Regiment „Nikolaus I. Kaiser von Rußland“ Nr.  5)" and a leading officer of the Austrian Armed Forces in the First Republic of Austria. Euridice (also Erudice or Eurydice) is an opera by Jacopo Peri, with additional music by Giulio Caccini.  It is the earliest surviving opera, Peri's earlier "Dafne" being lost.  (Caccini wrote his own "Euridice" even as he supplied music to Peri's opera, published this version before Peri's was performed, in 1600, and got it staged two years later.)  The libretto by Ottavio Rinuccini is based on books X and XI of Ovid's "Metamorphoses" Der Kaiser von Schexing is a German television series. Miloud Hadefi (Arabic: ميلود هدفي‎ ‎ ; March 12, 1949 in Oran – June 6, 1994) was an Algerian football player and manager.  Hedefi represented Algeria in two Football World Cup qualifying matches.  His preferred position was Libero.  He was nicknamed "the African Kaiser" by Pelé because of his similar style to German defender "Der Kaiser", Franz Beckenbauer. Der Kaiser von Atlantis oder Die Tod-Verweigerung ("The Emperor of Atlantis or The Disobedience of Death") is a one-act opera by Viktor Ullmann with a libretto by Peter Kien.  They collaborated on the work while interned in the Nazi concentration camp of Theresienstadt (Terezín) around 1943.  The Nazis did not allow it to be performed there. Maria Bard (7 July 1900 – 8 April 1944) was a German stage actress, who made a handful of films in the silent era for Rimax, her first husband Wilhelm Graaff's company.  By 1930, her marriage with Graaff was over, and she appeared with Werner Krauss in the stage production "Der Kaiser von Amerika" or "The King of America" and the two became involved.  Unfortunately, Krauss' wife discovered their affair and committed suicide; a year later, in 1931, Maria Bard married Werner Krauss.  Her third husband was actor Hannes Stelzer.  Bard committed suicide on 8 April 1944, apparently for political reasons.  On December 27, 1944, toward the end of World War II, Stelzer who was in the Luftwaffe at this point, died when his plane was shot down over the Eastern front.
Answer: opera