Title: Opera (1987 film)
Content:  Opera (also known and released as Terror at the Opera) is a 1987 Italian giallo horror film directed and co-written by Dario Argento and starring Cristina Marsillach, Urbano Barberini, Daria Nicolodi, and Ian Charleson. The film's plot focuses on a young soprano (Marsillach) who becomes involved in a series of murders being committed inside an opera house by a masked assailant. The film features music composed and performed by Brian Eno, Claudio Simonetti, and Bill Wyman. Opera was one of Argento's most commercially successful films, seeing 1,363,912 ticket sales in his native country of Italy. It is the second Dario Argento horror film to have THX audio certified and picture quality.
Title: Opera Factory
Content:  for the company to be supported by the ENO, but a permanent deal never materialised. However, with the proceeds from their productions and the support of the London Sinfonietta and later the South Bank as well as grants from Arts Council England, the London company survived until 1998. Its last production was And the Snake Sheds Its Skin, with text by David Freeman and music by the Senegalese pop composer Habib Faye. The Zurich branch of the Opera Factory continued in parallel until 1995 when it lost its subsidy from the city of Zurich. Opera Factory Zurich's last productions were a joint run of Britten's Curlew River and Purcell's Dido and Aeneas.
Title: Peter Gelb
Content:  for six years as executive producer of "The Metropolitan Opera Presents", the Met's series of televised opera broadcasts. Gelb produced 25 televised productions for the Met, including the 1990 telecast of Richard Wagner’s complete Der Ring des Nibelungen, conducted by James Levine. While at CAMI, Gelb produced and occasionally directed more than 50 programs for television featuring such artists as Herbert von Karajan and Mstislav Rostropovich. In 1992, Gelb produced both the stage and film versions of Julie Taymor’s first opera production, Oedipus Rex, for Seiji Ozawa’s Saito Kinen Festival. Also for that Japanese festival, in 1994 he commissioned an early opera staging by Robert Lepage, La Damnation de Faust. A re-conceived version of that production was later presented at the Met in the 2008–09 season.
Title: Oscar (opera)
Content:  manner of Hollywood. Almost everything in this sober, hagiographic spectacle is borrowed: from Britten, from Richard Strauss, from Maurice Jarre, from Shostakovich." The director of the premiere production was Kevin Newbury. Other members of the production team included Seán Curran (choreographer), David Korins (scenic designer), David Woolard (costume designer), and Rick Fisher (lighting designer). Merlin Holland travelled to Santa Fe for the premiere. Reviews of the opera's premiere generally praised the singers, the orchestra, conductor Evan Rogister, and the overall production values. Criticism focused on the weakness of the opera's dramaturgy, the hagiographic depiction of Oscar Wilde, and the derivative nature of the music:              
Title: Opera Factory
Content:  Opera Factory was an experimental opera ensemble founded by Australian director David Freeman. It operated in Zurich from 1976 to 1995 and in London from 1982 to 1998. In the 1980s when the company worked with the London Sinfonietta, its productions were billed as Opera Factory London Sinfonietta (OFLS). Known for its avant garde and often controversial productions, the company's 1986 Così fan tutte  was described by The Guardian s music critic, Andrew Clements as one of the "ten productions that changed British opera". Opera Factory aimed to bring the techniques of Peter Brook and Jerzy Grotowski to music drama. David Freeman wrote that it would "have the luxury of being able to question many of the assumptions about opera and its role in society which a large company, because of its very size, can afford neither the time nor the money to do". He expressed a similar sentiment in a 1989 profile in Opera magazine where he criticised the approach of major opera houses, such as the Royal Opera House, Metropolitan Opera, and La Scala, which viewed opera productions as largely defined by their costumes: "It's museum art taken to its logical conclusion."
Title: Opera House (1961 film)
Content:  Opera House is a 1961 Indian Hindi-language mystery film produced by A.A. Nadiadwala and directed by P.L. Santoshi. The film stars Ajit, B. Saroja Devi, K.N. Singh and Lalita Pawar among others.
Title: Die Opernprobe
Content:  Die Opernprobe was recorded in 1951, the 100th anniversary of the premiere, with singers including Helmut Krebs, Lisa Otto and the RIAS Kammerchor. A 1974 recording, with the choir and orchestra of the Bavarian State Opera conducted by Otmar Suitner, features Regina Marheineke, Nicolai Gedda, Klaus Hirte and Walter Berry, among others.
Title: The Marriage (opera)
Content:  television premiere, The Marriage was a triumphant success. As usual with almost all of the NBC Opera Theatre productions, Chotzinoff served as producer and Adler served as music director/conductor. John Block directed the production, Otis Riggs designed the sets, and Liz Gillan designed the costumes. Downes wrote in his review that "The production was of an excellent quality in the 1840s Russian costumes and scenic designs, and in the admirable level of the singing and English Diction. The show was produced and directed by master hands, in a way that would have made a less interesting score, less well designed for television presentation, worth while." Downes further praised Martinů for his successful marriage of the music with the text, stating the work "has droll characterization, adroit instrumental commentary, and certain motival phrases that bind the beginning and the end of the opera amazingly together."
Title: Opera Lyra Ottawa
Content:  The company was founded in 1984 in response to the National Arts Center's decision to end further opera productions due to budget constraints. Opera Lyra's founder and first Artistic Director was Diana Gilchrist, a young Canadian soprano at the very start of her career. Initially the company performed operas in chamber versions with piano accompaniment in the tiny York Street Theatre in Ottawa. Its first production was Mozart's The Impresario (in which Gilchrist sang Madame Silberklang as well as directing and producing the show). This was followed by Telemann's Pimpinone and the premiere of John Burge's chamber opera The Master's House which had 
Title: The Scarlet Ibis
Content:  The story was developed into an opera by composer Stefan Weisman with librettist David Cote. The opera was co-produced by New York City's Beth Morrison Projects and HERE Arts Center in association with American Opera Projects, and premiered in the PROTOTYPE Opera Festival on January 8, 2015. New York Times critic, David Allen, called the opera "a moving, intense and dignified creation." The opera was produced in January 2019 by the Boston Opera Collaborative and February 2019 by the Chicago Opera Theater.

Question: Who was the producer of Opera?
Answer: Dario Argento.
Sirio Bernadotte.