Question: Which opera is by Christoph Willibald Gluck, Iphigénie en Tauride or Der Barbier von Bagdad?

full_context: Document 1: Iphigénie en Tauride (Piccinni): Iphigénie en Tauride ("Iphigeneia in Tauris") is a tragédie lyrique in four acts by Niccolò Piccinni, which was first performed on 23 January 1781 by the Académie royale de musique (the Paris Opéra) in the second Salle du Palais-Royal. The opera's libretto, by Alphonse du Congé Dubreuil, is based on a play of the same name by Claude Guimond de La Touche, although the ultimate source was the tragedy "Iphigeneia in Tauris" by Euripides.
Document 2: Bluebeard's Castle: Bluebeard's Castle (Hungarian: A kékszakállú herceg vára ; literally: "The Blue-Bearded Duke's Castle") is a one-act opera by Hungarian composer Béla Bartók. The libretto was written by Béla Balázs, a poet and friend of the composer, and is written in Hungarian, based on the French literary tale "La Barbe bleue" by Charles Perrault. The opera lasts only a little over an hour and there are only two singing characters onstage: Bluebeard ("Kékszakállú "), and his new wife Judith ("Judit " ); the two have just eloped and Judith is coming home to Bluebeard's castle for the first time.
Document 3: Christoph Willibald Gluck: Christoph Willibald (Ritter von) Gluck (] ; 2 July 1714 – 15 November 1787) was a composer of Italian and French opera in the early classical period. Born in the Upper Palatinate (now part of Germany) and raised in Bohemia, he gained prominence at the Habsburg court at Vienna, where he brought about the practical reform of opera's dramaturgical practices that many intellectuals had been campaigning for over the years. With a series of radical new works in the 1760s, among them "Orfeo ed Euridice" and "Alceste", he broke the stranglehold that Metastasian "opera seria" had enjoyed for much of the century.
Document 4: Iphigénie en Tauride: Iphigénie en Tauride ("Iphigenia in Tauris") is a 1779 opera by Christoph Willibald Gluck in four acts. It was his fifth opera for the French stage. The libretto was written by Nicolas-François Guillard.
Document 5: The Bartered Bride: The Bartered Bride (, "The Sold Bride") is a comic opera in three acts by the Czech composer Bedřich Smetana, to a libretto by Karel Sabina. The work is generally regarded as a major contribution towards the development of Czech music. It was composed during the period 1863–66, and first performed at the Provisional Theatre, Prague, on 30 May 1866 in a two-act format with spoken dialogue.
Document 6: Der Barbier von Bagdad: Der Barbier von Bagdad ("The Barber of Baghdad") is a comic opera in two acts by Peter Cornelius to a German libretto by the composer, based on "The Tale of the Tailor" and "The Barber’s Stories of his Six Brothers" in "One Thousand and One Nights". The first of three operas by Cornelius, the piece was first performed at the Hoftheater in Weimar on 15 December 1858.
Document 7: Iphigénie en Tauride (Desmarets and Campra): Iphigénie en Tauride (English: "Iphigeneia in Tauris") is an opera by the French composers Henri Desmarets and André Campra. It takes the form of a "tragédie en musique" in a prologue and five acts. The libretto is by Joseph-François Duché de Vancy with additions by Antoine Danchet. Desmarets had begun work on the opera around 1696 but abandoned it when he was forced to go into exile in 1699. Campra and his regular librettist Danchet took up the piece and wrote the prologue, most of Act Five, two arias in Act One, an aria for Acts Two and Three, and two arias for the fourth act. The plot is ultimately based on Euripides' tragedy "Iphigeneia in Tauris".
Document 8: Peter und Ännchen: "Peter und Ännchen" premiered on 29 September 1809 in the theatre of the Ludwigsburg Palace near Stuttgart. The opera was popular in Germany in its day and a version of the score for voice and piano was published by Breitkopf & Härtel. It was also performed in Paris in 1810 as "Pierre et Annette". Franz Carl Hiemer had written the libretto for Abeille's first opera, "Amor und Psyche" (1800) as well as the libretti for Carl Maria von Weber's operas "Silvana" and "Abu Hassan".
Document 9: Nicolas-François Guillard: Nicolas-François Guillard (16 January 1752 – 26 December 1814) was a French librettist. He was born in Chartres and died in Paris, the recipient of a government pension in recognition of his work writing librettos. He was also on "Comité de Lecture" of the Paris Opéra. One of the foremost of the French librettist of his generation, he wrote libretti for many noted composers of the day, including Salieri ("Les Horaces") and in particular Sacchini ("Oedipe à Colone", amongst many others). His most famous work is "Iphigénie en Tauride", his first libretto, set by Gluck after the composer had initially rejected it. Gluck collaborated with Guillard to heavily recast the libretto, not only to suit Gluck's artistic preferences, but also to accommodate pre-existing music that Gluck borrowed, both from himself and from other composers, when composing the opera.
Document 10: Iphigénie en Tauride discography: This is a discography of Iphigénie en Tauride, an opera by Christoph Willibald Gluck, first performed at the Paris Opéra on May 18, 1779.
Document 11: Armide (Gluck): Gluck set the same libretto Philippe Quinault had written for Lully in 1686, based on Torquato Tasso's "Gerusalemme liberata" ("Jerusalem Delivered"). Gluck seemed at ease in facing French traditions head-on when he composed "Armide". Lully and Quinault were the very founders of serious opera in France and "Armide" was generally recognized as their masterpiece, so it was a bold move on Gluck's part to write new music to Quinault's words. A similar attempt to write a new opera to the libretto of "Thésée" by Jean Joseph de Mondonville in 1765 had ended in disaster, with audiences demanding it be replaced by Lully's original. By utilizing "Armide", Gluck challenged the long-standing and apparently inviolable ideals of French practice, and in the process he revealed these values capable of renewal through "modern" compositional sensitivities. Critical response and resultant polemic resulted in one of those grand imbroglios common to French intellectual life. Gluck struck a nerve in French sensitivities, and whereas "Armide" was not one of his more popular works, it remained a critical touchstone in the French operatic tradition and was warmly praised by Berlioz in his "Memoirs". Gluck also set a minor fashion for resetting Lully/Quinault operas: Gluck's rival Piccinni followed his example with "Roland" in 1778 and "Atys" in 1780; in the same year, Philidor produced a new "Persée"; and Gossec offered his version of "Thésée" in 1782. Gluck himself is said to have been working on an opera based on "Roland", but he abandoned it when he heard Piccinni had taken on the same libretto.
Document 12: Iphigénie en Aulide: Iphigénie en Aulide ("Iphigeneia in Aulis") is an opera in three acts by Christoph Willibald Gluck, the first work he wrote for the Paris stage. The libretto was written by François-Louis Gand Le Bland Du Roullet and was based on Jean Racine's tragedy "Iphigénie". It was premiered on 19 April 1774 by the Paris Opéra in the second Salle du Palais-Royal and revived in a slightly revised version the following year.
Document 13: Spieloper: In the 19th century, Spieloper ('opera play') was understood to mean a light opera genre, developed from Singspiel. Works typical of the genre include those by Albert Lortzing, such as "Zar und Zimmermann", and Otto Nicolai's "The Merry Wives of Windsor". A key difference between Spieloper and Singspiel on the one hand, and opera buffa on the other, is that the two former genres contain spoken dialogues instead of recitatives, which is why Conradin Kreutzer's "Das Nachtlager in Granada" and Friedrich von Flotow's "Martha" do not belong to this genre.
Document 14: Boccaccio (operetta): Boccaccio, oder Der Prinz von Palermo ("Boccaccio, or the Prince of Palermo") is an operetta in three acts by Franz von Suppé to a German libretto by Camillo Walzel and Richard Genée, based on the play by Jean-François Bayard, Adolphe de Leuven, Léon Lévy Brunswick and Arthur de Beauplan, based in turn on "The Decameron" by Giovanni Boccaccio.
Document 15: Abu Hassan: Abu Hassan is a comic opera in one act by Carl Maria von Weber to a German libretto by , based on a story in "One Thousand and One Nights". It was composed between 11 August 1810 and 12 January 1811 and has set numbers with recitative and spoken dialogue. The work is a Singspiel in the then popular Turkish style.
ground_truth: Iphigénie en Tauride