Dafne is the earliest known work that, by modern standards, could be considered an opera.
 The libretto by Ottavio Rinuccini survives complete; the mostly-lost music was completed by Jacopo Peri, but at least two of the six surviving fragments are by Jacopo Corsi.
 "Dafne" was first performed during Carnival of 1598 (1597 old style) at the Palazzo Corsi.
This list provides a guide to opera composers, as determined by their presence on a majority of compiled lists of significant opera composers.
 (See the "Lists Consulted" section for full details.)
 The composers run from Jacopo Peri, who wrote the first ever opera in late 16th century Italy, to John Adams, one of the leading figures in the contemporary operatic world.
 The brief accompanying notes offer an explanation as to why each composer has been considered major.
 Also included is a section about major women opera composers, compiled from the same lists.
 For an introduction to operatic history, see opera.
 The organisation of the list is by birthdate.
Jacopo Corsi (17 July 1561 – 29 December 1602) was an Italian composer of the late Renaissance and early Baroque and one of Florence's leading patrons of the arts, after only the Medicis.
 His best-known work is "Dafne" (1597/98), whose score he wrote in collaboration with Jacopo Peri.
 Six fragments of the score have survived, two by Corsi and four by Peri.
 The libretto, by Ottavio Rinuccini, has survived intact.
 Despite priority quibbles at the time, Dafne is generally accepted as the first opera.
The Mémoires de Hector Berlioz are an autobiography by French composer Hector Berlioz.
 First serialised in several contemporary journals including "Journal des Débats" and "Le Monde Illustré", their compilation into one book was completed on New Year's Day, 1865 and after much proof-reading, an initial printing of 1200 was carried out in July.
 After distributing some copies to certain friends, they were put aside until Berlioz died.
 After Berlioz's death in 1869, they were published in 1870.
 They provide an extremely colourful, if biased, account of Berlioz's life, and are invaluable to anyone with an interest in the artistic life of the time.
Louis-Hector Berlioz (] (English: ); 11 December 1803 – 8 March 1869) was a French Romantic composer, best known for his compositions "Symphonie fantastique" and "Grande messe des morts" (Requiem).
 Berlioz made significant contributions to the modern orchestra with his "Treatise on Instrumentation".
 He specified huge orchestral forces for some of his works, and conducted several concerts with more than 1,000 musicians.
 He also composed around 50 songs.
 His influence was critical for the further development of Romanticism, especially in composers like Richard Wagner, Nikolai Rimsky-Korsakov, Franz Liszt, Richard Strauss, and Gustav Mahler.
Jacopo Peri (Zazzerino) (20 August 156112 August 1633) was an Italian composer and singer of the transitional period between the Renaissance and Baroque styles, and is often called the inventor of opera.
 He wrote the first work to be called an opera today, "Dafne" (around 1597), and also the first opera to have survived to the present day, "Euridice" (1600).
Benvenuto Cellini is an opera semiseria in two acts with music by Hector Berlioz and libretto by Léon de Wailly and Henri Auguste Barbier.
 It was the first of Berlioz's operas, premiered at the Académie Royale de Musique (Salle Le Peletier) on 10 September 1838.
 The story is inspired by the memoirs of the Florentine sculptor Benvenuto Cellini, although the elements of the plot are largely fictional.
 The opera is technically very challenging and rarely performed.
 However, the overture to the opera sometimes features in symphony orchestra programs, as does the concert overture "Le carnaval romain" which Berlioz composed from material in the opera.
Euridice is an opera in a prologue and one act by the Italian composer Giulio Caccini.
 The libretto, by Ottavio Rinuccini, had already been set by Caccini's rival Jacopo Peri in 1600.
 Caccini's version of "Euridice" was first performed at the Pitti Palace, Florence on 5 December 1602.
 Caccini hurriedly prepared the score for the press and published it six weeks before Peri's version appeared.
L'Orfeo (SV 318) (] ), sometimes called La favola d'Orfeo ] , is a late Renaissance/early Baroque "favola in musica", or opera, by Claudio Monteverdi, with a libretto by Alessandro Striggio.
 It is based on the Greek legend of Orpheus, and tells the story of his descent to Hades and his fruitless attempt to bring his dead bride Eurydice back to the living world.
 It was written in 1607 for a court performance during the annual Carnival at Mantua.
 While Jacopo Peri's "Dafne" is generally recognised as the first work in the opera genre, and the earliest surviving opera is Peri's "Euridice", "L'Orfeo" is the earliest that is still regularly performed.
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"

Question: Who is often called the inventor of opera, Hector Berlioz or Jacopo Peri ?
Answer: Jacopo Peri