Styled a "festa teatrale", "Le feste d'Apollo" consists of a prologue and three self-contained acts on the model of French "opéra-ballet" (the court of Parma was passionately interested in French culture).
 Gluck knew the Archduchess Maria Amalia well as she had sung in two of his operas, "Il Parnaso confuso" and "La corona", in Vienna.
 The composer recycled a lot of music from his earlier operas in the score of "Le feste".
 In fact, the whole of the third act, "Orfeo", is a shorter reworking of his most famous piece, "Orfeo ed Euridice" (1762).
 The overture to the prologue is taken from "Telemaco".
 Gluck later reused some of the choruses in two of the operas he wrote for Paris, "Iphigénie en Aulide" and "Iphigénie en Tauride".
L'anima del filosofo, ossia Orfeo ed Euridice ("The Soul of the Philosopher, or Orpheus and Euridice"), Hob.
 28/13, is an opera in Italian in four acts by Joseph Haydn, the last he ever wrote.
 The libretto, by Carlo Francesco Badini, is based on the myth of Orpheus and Euridice as told in Ovid's "Metamorphoses".
 Composed in 1791, the opera was never performed during Haydn's lifetime.
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.
Pierre-Louis Moline (  1740 – 20 March 1820) was a prolific French dramatist, poet and librettist.
 His play "La Réunion du six août" was one of the longest-running patriotic pieces during the time of the French Revolution with 52 performances at the Paris Opéra.
 He also wrote the epitaph for the tomb of Jean-Paul Marat.
 However, he is best remembered today for having adapted Calzabigi's libretto for Gluck's "Orphée et Euridice" (a reworked version of his "Orfeo ed Euridice").
Paride ed Elena (] ; "Paris and Helen") is an opera by Christoph Willibald Gluck.
 It is the third of Gluck's so-called reform operas for Vienna, following "Alceste" and "Orfeo ed Euridice", and the least often performed of the three.
 Like its predecessors, the libretto was written by Ranieri de' Calzabigi.
 The opera tells the story of the events between the Judgment of Paris and the flight of Paris and Helen to Troy.
 It was premiered at the Burgtheater in Vienna on 3 November 1770.
Wilhelmine Ritter was a German operatic mezzo-soprano.
 Little is known about the artist and the details about her birth and training are unknown.
 She was a member of the Bavarian State Opera in Munich from 1866 through 1871.
 While there she notably created the roles of Flosshilde in Richard Wagner's "Das Rheingold" on 22 September 1869 and Grimgerde (one of the Valkyries) in Wagner's "Die Walküre" on 26 June 1869.
 Her last performance at the house was as Orfeo in Christoph Willibald Gluck's "Orfeo ed Euridice" in 1871.
 She got married soon after and retired permanently from the stage.
 Currently no further biographical details about Ritter have surfaced.
Orfeo ed Euridice (French version: Orphée et Eurydice ; English: "Orpheus and Eurydice") is an opera composed by Christoph Willibald Gluck based on the myth of Orpheus, set to a libretto by Ranieri de' Calzabigi.
 It belongs to the genre of the "azione teatrale", meaning an opera on a mythological subject with choruses and dancing.
 The piece was first performed at the Burgtheater in Vienna on 5 October 1762 in the presence of Empress Maria Theresa.
 "Orfeo ed Euridice" is the first of Gluck's "reform" operas, in which he attempted to replace the abstruse plots and overly complex music of "opera seria" with a "noble simplicity" in both the music and the drama.
Allen Moyer (born 1958) is an American set designer particularly known for his work in operas and Broadway musicals.
 He grew up in Schuylkill Haven, Pennsylvania and holds a BA from the Pennsylvania State University and a MFA degree from New York University's Tisch School of the Arts where he studied under John Conklin.
 His designs have appeared in celebrated productions at the New York City Opera, the San Francisco Opera, the Santa Fe Opera, the Opera Theatre of Saint Louis, and the Seattle Opera.
 He notably staged the world premiere of Stewart Wallace's "Harvey Milk" at the Houston Grand Opera in 1995 and the world premiere of Ricky Ian Gordon's "The Grapes of Wrath" at the Minnesota Opera in 2007.
 He designed his first set for the Metropolitan Opera for their new production of Gluck's "Orfeo ed Euridice" which premiered on May 2, 2007.
Der Freischütz , Op. 77, J. 277, (usually translated as "The Marksman" or "The Freeshooter") is a German opera with spoken dialogue in three acts by Carl Maria von Weber with a libretto by Friedrich Kind.
 It premiered on 18 June 1821 at the Schauspielhaus Berlin.
 It is considered the first important German Romantic opera, especially in its national identity and stark emotionality.
The following discography for Gluck's opera "Orfeo ed Euridice" is mainly based on the research of Giuseppe Rossi, which appeared in the programme notes to the performance of the work at the 70th Maggio Musicale Fiorentino in 2007, under the title "Discografia – Christoph Willibald Gluck – Orfeo ed Euridice (Orphée et Eurydice)".
 Rossi's data has been checked against the sources referenced in the notes.

Question: Which opera premiered first, Der Freischütz or Orfeo ed Euridice?
Answer: Orfeo ed Euridice