Die Frau ohne Schatten (The Woman without a Shadow), Op. 65, is an opera in three acts by Richard Strauss with a libretto by his long-time collaborator, the poet Hugo von Hofmannsthal.
 It was written between 1911 and either 1915 or 1917.
 When it premiered in Vienna on 10 October 1919, critics and audiences were unenthusiastic.
 Many cited problems with Hofmannsthal's complicated and heavily symbolic libretto.
 However, it is now a standard part of the operatic repertoire.
Ermanno Wolf-Ferrari (born Ermanno Wolf) (January 12, 1876 – January 21, 1948) was an Italian composer and teacher.
 He is best known for his comic operas such as "Il segreto di Susanna" (1909).
 A number of his works were based on plays by Carlo Goldoni, including "Le donne curiose" (1903), "I quatro rusteghi" (1906) and "Il campiello" (1936).
Richard Mayr (18 November 1877, in Henndorf – 1 December 1935, in Vienna) was an Austrian operatic bass-baritone who was particularly admired for his performances in works by Wolfgang Amadeus Mozart, Richard Wagner and Richard Strauss.
 He notably created the role of Barak, the Dyer in the world premiere of Strauss's "Die Frau ohne Schatten".
Il segreto di Susanna (English: "Susanna's Secret", German: "Susannens Geheimnis") is an intermezzo in one act by Ermanno Wolf-Ferrari to an Italian libretto by Enrico Golisciani.
 The premiere of the opera was in German, in a translation by Max Kalbeck, at the Hoftheater in Munich on 4 December 1909.
This is a list of recordings of Die Frau ohne Schatten, a three-act opera by Richard Strauss with a German-language libretto by Hugo von Hofmannsthal.
 The work was first performed in Vienna on 10 October 1919.
Glenn Winslade (born 1958) is an Australian operatic tenor known for his interpretations of dramatic roles such as Florestan in "Fidelio", the title role in "Idomeneo", the title role in "La clemenza di Tito", Erik in "The Flying Dutchman", the title role in "Rienzi", the title role in "Lohengrin", the title role in "Tannhäuser", the Emperor in "Die Frau ohne Schatten", Apollo in "Daphne", Bacchus in "Ariadne auf Naxos" and Max in "Der Freischütz".
Jan-Hendrik Rootering (born 18 March 1950 in Wedingfeld near Flensburg) is a German-born operatic bass, son of the Dutch tenor Hendrikus Rootering from whom he had his first lessons.
 After further study at Hamburg's "Musikhochschule" he began singing minor roles with the Staatsoper Hamburg and made a debut at the Bayerischen Staatsoper München in 1982 as the Spirit Messenger in Die Frau ohne Schatten.
 In 1987 he received the title of "Bayerischer Kammersänger".
 Mr. Rootering was the bass soloist in the Beethoven Ninth Symphony conducted by Leonard Bernstein in celebration of the fall of the Berlin wall -- in the no-longer-divided city of Berlin -- at Christmastime 1989.
Ellen Shade is an American operatic soprano from New York.
 Her repertoire includes the Kaiserin in "Die Frau ohne Schatten", the Marschallin "Der Rosenkavalier", Chrysothemis "Elektra", Ariadne "Ariadne auf Naxos", Arabella, Katya Kabanova, Aida, Desdemona "Otello", Amelia "Un ballo in Maschera", Amelia "Simon Boccanegra", Sieglinde "Die Walkure", Elsa "Lohengrin", Elisabeth "Tannhauser", Eva "Die Meistersinger von Nurnberg".
 In Europe she has appeared at La Scala Milan, the Royal Opera House, Covent Garden, the Bastille and the Chatelet in Paris and in Vienna, Salzburg Festival, Berlin, Hamburg, Frankfurt [Article Reference], Stuttgart, Amsterdam, Brussels, Geneva and Athens.
 In North America she has performed with virtually all the major opera companies, including the Metropolitan Opera New York, Chicago, San Francisco, Los Angeles, Houston, Dallas, Seattle, Santa Fe, and the Canadian Opera in Toronto.
Friedrich Brodersen (1 December 1873 - 19 March 1926) was a German operatic baritone.
 Born in Bad Boll, he studied singing with Heinrich Bertram.
 He made his professional opera debut in 1900.
 He created roles in several world premieres during his career, including Pantalone in Ermanno Wolf-Ferrari's "Le donne curiose" (1903), Count Gil in Wolf-Ferrari's "Il segreto di Susanna" (1909), Simone Trovai in Erich Wolfgang Korngold's "Violanta" (1916), Morone in Hans Pfitzner's "Palestrina" (1917), Sang in Heinrich Rohr's "Das Vaterunser", and roles in Paul von Klenau's "Sulamith" (1913), and Walter Braunfels's "Die Vögel" (1920).
Mark Delavan is an American operatic bass-baritone.
 He made his professional debut in 1986 at the San Francisco Opera in a small role in Giuseppe Verdi's "Don Carlos".
 He spent the next three years performing in numerous comprimario roles with the company.
 He has since returned to that opera house to sing Scarpia in Giacomo Puccini's "Tosca" (2004, with Carol Vaness in the title role) and Wotan in Richard Wagner's "The Ring Cycle" (2008, 2010, and 2011).
 In 2001 he made his debut at the Metropolitan Opera as Amonasro in Verdi's "Aida" with Deborah Voigt in the title role, Luciano Pavarotti as Radamès, Olga Borodina as Amneris, and James Levine conducting.
 He has since been heard at the Met as Alfio in Pietro Mascagni's "Cavalleria rusticana", Carlo Gérard in "Andrea Chénier", Count Tomsky in "The Queen of Spades", Don Carlo in Verdi's "La Forza del Destino", the Messenger in Richard Strauss' "Die Frau ohne Schatten", Scarpia, and the title roles in Verdi's "Nabucco", Verdi's "Rigoletto", and Verdi's "Simon Boccanegra".

Question: Which of the following musical pieces premiered first - Il segreto di Susanna or Die Frau ohne Schatten?
Answer: Il segreto di Susanna