question: Are both pieces The Immortal Hour and L'incoronazione di Poppea an opera?
answer: yes
context: Title: The Immortal Hour
  Passage: The Immortal Hour is an opera by English composer Rutland Boughton.  Boughton adapted his own libretto from the works of Fiona MacLeod, a pseudonym of writer William Sharp.
  Title: L'incoronazione di Poppea discography
  Passage: These lists show the audio and visual recordings of L'incoronazione di Poppea by Claudio Monteverdi.  The opera was premiered in Venice in 1642-43, but after a 1651 revival in Naples it remained unperformed for 250 years.  It began to enter the general opera repertory in the 1960s, and thereafter was increasingly performed in leading opera houses and festivals.
  Title: L'incoronazione di Poppea
  Passage: L'incoronazione di Poppea (SV 308, "The Coronation of Poppaea") is an Italian opera by Claudio Monteverdi, with a libretto by Giovanni Francesco Busenello, first performed at the Teatro Santi Giovanni e Paolo in Venice during the 1643 carnival season.  One of the first operas to use historical events and people, it describes how Poppaea, mistress of the Roman emperor Nero, is able to achieve her ambition and be crowned empress.  The opera was revived in Naples in 1651, but was then neglected until the rediscovery of the score in 1888, after which it became the subject of scholarly attention in the late 19th and early 20th centuries.  Since the 1960s, the opera has been performed and recorded many times.
  Title: Francesco Sacrati
  Passage: Francesco Sacrati (17 September 1605 in Parma, Italy – 20 May 1650 in Modena, Italy) was an Italian composer of the Baroque era, who played an important role in the early history of opera.  He wrote for the Teatro Novissimo in Venice as well as touring his operas throughout Italy.  His most famous piece is "La finta pazza" ("The Feigned Madwoman", 1641), said to be the first opera ever performed in France (in 1645).  The manuscript of this work was long thought to be lost but a touring edition of the manuscript was discovered by musicologist Lorenzo Bianconi in 1984.  Some of the music bears striking similarities to the score of Monteverdi's "L'incoronazione di Poppea", prompting scholars to speculate that Sacrati had a part in composing the surviving version of that opera.  The United States premiere of "La finta pazza", and first performance outside Europe, occurred in April 2010 at Yale University.
  Title: Ulrik Cold
  Passage: Ulrik Thesrup Cold (born 15 May 1939, Copenhagen – died 13 October 2010, Copenhagen) was a Danish operatic bass.  In 1963 he made his professional opera debut at the Royal Danish Theatre (RDT) as Seneca in Claudio Monteverdi's "L'incoronazione di Poppea".  He was active at the RDT for the next several decades and served as the director of the RDT from 1975-1977.
  Title: Gregory Reinhart
  Passage: Gregory Reinhart (born June 18, 1951 in Pavilion, New York) is an American bass opera singer.  He is noted for an extremely wide repertory which ranges from early music to the world premieres of several contemporary operas including Lowell Liebermann's "The Picture of Dorian Gray", Philippe Manoury's "K.. ." , and Pascal Dusapin's "Perelà, uomo di fumo".  He has been praised in "The Metropolitan Opera Guide to Recorded Opera" for his performance in Monteverdi's "L'Incoronazione di Poppea" as one of the finest Senecas on record with "a magnificent bass voice: firm and clear throughout its wide range".
  Title: Ottone in villa
  Passage: Ottone in villa ("Otho at his villa", RV 729) is an opera in three acts by Antonio Vivaldi to an Italian libretto by Domenico Lalli (the pseudonym of Sebastiano Biancardi).  It was Vivaldi's first opera and premiered on 17 May 1713 at the Teatro delle Grazie in Vicenza.  Lalli's pastoral drama is set in ancient Rome and was a condensed adaptation of Francesco Maria Piccioli's satirical libretto for Carlo Pallavicino's opera "Messalina" (1679).  However, Lalli changed several of the characters in Piccioli's libretto.  Messalina became an invented character, Cleonilla.  Emperor Claudius became another Roman emperor, Otho (Ottone), who had already appeared as a protagonist in Monteverdi's "L'incoronazione di Poppea" (1642) and in Handel's "Agrippina" (1709).
  Title: L'incoronazione di Dario (Perti)
  Passage: L'incoronazione di Dario ("The Coronation of Darius") is an opera in three acts composed by Giacomo Antonio Perti to a libretto by Adriano Morselli (revised by Giorgio Maria Raparini).  It premiered on January 13, 1686 at the Teatro Malvezzi in Bologna.  Morselli originally wrote the libretto for Domenico Freschi's opera "Dario" which premiered at the Teatro San Angelo in Venice in 1685.  Other later uses of the libretto include Giuseppe Aldrovandini's 1705 "L'incoronazione di Dario" (with the libretto revised by Andrea del Pò) and Vivaldi's 1717 "L'incoronazione di Dario" (with the libretto revised by an unknown author).
  Title: Lost operas by Claudio Monteverdi
  Passage: The Italian composer Claudio Monteverdi (1567–1643), in addition to a large output of church music and madrigals, wrote prolifically for the stage.  His theatrical works were written between 1604 and 1643 and included ten operas, of which three—"L'Orfeo" (1607), "Il ritorno d'Ulisse in patria" (1640) and "L'incoronazione di Poppea" (1643)—have survived with their music and librettos intact.  In the case of the other seven operas, the music has disappeared almost entirely, although some of the librettos exist.  The loss of these works, written during a critical period of early opera history, has been much regretted by commentators and musicologists.
  Title: Teatro Santi Giovanni e Paolo
  Passage: The Teatro Santi Giovanni e Paolo (often written as Teatro SS.  Giovanni e Paolo) was a theatre and opera house in Venice located on the Calle della Testa, and takes its name from the nearby Basilica of Santi Giovanni e Paolo, Venice.  Built by the Grimani family in 1638, in its heyday it was considered the most beautiful and comfortable theatre in the city.  The theatre played an important role in the development of opera and saw the premieres of several works by Francesco Cavalli, as well as Monteverdi's "Il ritorno d'Ulisse in patria" and "L'incoronazione di Poppea".
citations: L'incoronazione di Poppea The Immortal Hour