Question: Eleanora Ehrenberg stared in what opera that was first performed at the Provisional Theatre, Prague in 1866?

Context paragraphs:
The Kiss (opera): The Kiss (Czech: Hubička ) is an opera in two acts, with music by Bedřich Smetana and text by Eliška Krásnohorská, based on a novel by Karolina Světlá.  It received its first performance at the Provisional Theatre in Prague on 7 November 1876.

Jan Nepomuk Maýr: Jan Nepomuk Maýr (sometimes spelled Mayr, Mayer, or Maier) (17 February 1818 – 25 October 1888) was a Czech operatic tenor, opera director, conductor, composer, and music educator.  He is best remembered today for serving as the first director/principal conductor of the Provisional Theatre in Prague.

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.

Antonín Švorc: Antonín Švorc (12 February 1934, Jaroměř – 21 February 2011) was a Czech operatic bass-baritone.  He studied with J. Berlíka at the Prague Conservatory before making his professional opera debut at the Liberec Theatre in 1955 where he was committed for one year.  He joined the roster of principal artists at the National Theatre in Prague in 1956.  He performed at that theatre until 1962 when he joined the Prague State Opera (PSO) where he performed for the next several decades.  In 1985 he was named a People's Artist of Czechoslovakia and in 2003 he was honored with a Thalia Award.  Retired from the stage, he taught on the voice faculty at the Prague Conservatory.

The Bartered Bride discography: This list is a discography of The Bartered Bride (; German: Die verkaufte Braut) by Bedřich Smetana.  The opera was first performed, in its original two-act format, at the Provisional Theatre, Prague, on 30 May 1866.  After substantial revisions it was premiered in its extended three-act form at the Provisional Theatre on 25 September 1870.

Provisional Theatre (Prague): The Prague Provisional Theatre (, ] ) was erected in 1862 as a temporary home for Czech drama and opera until a permanent National Theatre could be built.  It opened on 18 November 1862 and functioned for 20 years, during which time over 5,000 performances were presented.  Between 1866 and 1876 the theatre staged the premieres of four of Bedřich Smetana's operas, including "The Bartered Bride".  The Provisional Theatre building was eventually incorporated into the structure of the National Theatre, which opened its doors on 11 June 1881.

La pravità castigata: La pravità castigata ("Depravity Punished") is a 1730 pastiche with music by multiple composers and an Italian language libretto by Antonio Denzio.  It is the first 18th-century opera based on the Don Juan legend.  It was also the first opera ever produced that retains the original setting and at least some of the original character names derived from early 17th-century dramatic prototypes of the Don Juan legend, the most important of which is Tirso de Molina's play El burlador de Sevilla y convidado de piedra.  "La pravità castigata" was originally performed during Lent of 1730 in the opera theater of Franz Anton von Sporck in Prague, then revived with new music by Eustachio Bambini in Brno in 1734.  Unfortunately, the Brno performance was regarded as the original production for decades, and a published transcription of the libretto (which is missing two scenes from the Prague production) identifies it incorrectly as an anonymous text first performed in Brno.

Antonio Denzio: Antonio Denzio (23 September 1689 – after 1763) was an Italian impresario, tenor, and librettist.  Born in Venice to a family of musicians and operatic personnel, he pursued a career mainly as a singer until 1724, when he traveled to Bohemia as a member of the opera company of Antonio Maria Peruzzi, probably his uncle.  Peruzzi had the idea of bringing an Italian opera company to central Europe to perform first in Prague, then Dresden and Leipzig.  The company was first brought to Bohemia under the patronage of Count Franz Anton von Sporck, who had it play at his palace at Kuks in northwest Bohemia in the summer of 1724.  The performances were so successful that he permitted the company to perform free of charge in his palace in Prague.  After disagreements with Peruzzi, Denzio was able to supplant him as impresario before the end of the year 1724 and continued productions in the Sporck palace until 1735.  Peruzzi left with some of the Peruzzi-Denzio players to found the Breslau Opera.  Denzio's opera theater at Sporck's palace was the first standing opera theater in the city.  His productions were popular with the Bohemian nobility until about 1729, after which Denzio's finances deteriorated.  Count Sporck provided no financial assistance to the company except the free use of his theater, and he allowed it to fail.  The company went bankrupt and Denzio was forced to spend time in debtors' prison.  During its heyday, Denzio was able to attract at least one of the principal singing stars in Italy to Prague each season.  The most prominent of all was Margherita Gualandi, who was forced to come to Prague after being blackballed in Italy for bad behavior.  Denzio sought the assistance of Antonio Vivaldi in engaging singers for his company, and the composer sent music.  In the early 1730s, Vivaldi came himself to Prague.  Some of the music for one of his operas composed for Prague, "Argippo", has only recently been re-discovered.

Ludmila Vernerová: Ludmila Vernerová (born 1962) is a Czech operatic soprano and the niece of oboist Pavel Verner.  After graduating from the Academy of Performing Arts in Prague, she was a regular performer at the Prague Chamber Opera in the mid 1980s.  In 1987 she joined the Prague National Theatre where she performed for 12 years, Since 1999 she has been a member of the Prague State Opera.  Among the many roles she has created on stage are Angelica in "Orlando furioso", Belinda in "Dido and Aeneas", Countess Almaviva in "The Marriage of Figaro", Donna Anna in "Don Giovanni", Fiordiligi in "Così fan tutte", Isabella in "Robert le diable", Lucy in "The Beggar's Opera", Micaela in "Carmen", Musetta in "La bohème", Pamina in "The Magic Flute", and the title roles in "Alcina" and "Rodelinda".

Eleanora Ehrenbergů: Eleanora Ehrenbergů (sometimes spelled Eleanora Ehrenbergová or Eleanora Ehrenberg) (1 November 1832 – 30 August 1912) was a Czech operatic soprano.  In 1854 she made her professional opera debut at the Estates Theatre in the title role of Donizetti's "Lucia di Lammermoor".  In 1866 she created the role of Mařenka in the world première of Bedřich Smetana's "The Bartered Bride", and in 1868 she portrayed Jitka in the premiere of Smetana's "Dalibor".  She retired from the stage sometime in the 1880s.

Supporting paragraphs: Eleanora Ehrenbergů The Bartered Bride
Answer: The Bartered Bride