Question: What Czech operatic contralto had a close partnership with the composer of "The Bartered Bride"?

Context articles: Bernhard Bötel
Karin Branzell
Jana Sýkorová
The Bartered Bride (1932 film)
Karel Hruška
Skočná
Betty Fibichová
The Bartered Bride
Bedřich Smetana
Eleanora Ehrenbergů

Bernhard Bötel (1883–1953) was a German operatic tenor and actor who had an active career in Germany and Austria during the first half of the 20th century.
 He made recordings for several record labels during the early years of the recording industry, including His Master's Voice, Odeon Records, Polydor Records, Tri-Ergon, and Vox Records.
 On the stage he sang a variety of roles in operas and operettas from leading parts to comprimario roles.
 His stage repertoire included Belmonte in Wolfgang Amadeus Mozart's "Die Entführung aus dem Serail", Chapelou in Adolphe Adam's "Le postillon de Lonjumeau", Count Almaviva in Gioachino Rossini's "The Barber of Seville", Daniel in Franz Lehár's "The Merry Widow", the Duke of Mantua in Giuseppe Verdi's "Rigoletto", Gabriel von Eisenstein in Johann Strauss II's "Die Fledermaus", Indigo in Strauss' "Indigo und die vierzig Räuber", Jeník in Bedřich Smetana's "The Bartered Bride", Paolino in Domenico Cimarosa's "Il matrimonio segreto", Pâris in Jacques Offenbach's "La belle Hélène", Pietro in Franz von Suppé's "Boccaccio", and Wilhelm Meister in Ambroise Thomas' "Mignon".
Karin Branzell (24 September 189115 December 1974) was a Swedish operatic contralto (sometimes described as a mezzo-soprano), who had a prominent career at the Metropolitan Opera, New York, and in Europe.
 Her very wide range enabled her to sing both contralto roles and the occasional soprano role.
 She was particularly noted for her singing of the music of Richard Wagner, in roles such as Ortrud ("Lohengrin"), Venus ("Tannhäuser"), Erda ("Das Rheingold" and "Siegfried"), Brangäne ("Tristan und Isolde"), and Brunnhilde ("Die Walküre").
 She was considered on a par with Margarete Klose and Kerstin Thorborg as a Wagnerian contralto.
 Amneris ("Aida"), Dalila ("Samson et Dalila"), Herodias ("Salome"), and Clytemnestra ("Elektra") were among her other renowned roles.
Jana Sýkorová (born 9 June 1973) is a Czech operatic contralto.
 She has been a leading soloist with the Prague State Opera since 1999.
 Since 2002, she has been a permanent guest at the National Theatre in Prague and was made a permanent guest at the National Theatre in Brno in 2006.
The Bartered Bride (German: "Die verkaufte Braut" ) is a 1932 German film directed by Max Ophüls and based on the comic opera of the same name by Czech composer Bedřich Smetana.
Karel Hruška (14 June 1891 – 17 October 1966) was a Czech tenor, radio personality, and actor of the stage and film.
 He was an unusual singer for his day in that he recorded and performed both classical and popular music.
 Possessing a great comic talent, he specialized in creating character parts on the opera stage.
 He was a much loved Principál komediantů in Bedřich Smetana's "The Bartered Bride", notably portraying the role a total of 855 times during his career.
Skočná is a rapid Slavic folk-dance, normally in metre.
 Czech composers Antonín Dvořák and Bedřich Smetana used this dance, the latter in the third act of "The Bartered Bride" where it is danced by a circus troup and is often known as the Dance of the Comedians.
 Dvořák's 5th, 7th and 11th Slavonic Dances are in the form of the skočná.
Betty Fibichová (16 March 1846 – 20 May 1901) was a Czechoslovak opera singer and the wife of composer Zdeněk Fibich.
 The greatest Czech operatic contralto of her day, she enjoyed close artistic partnerships with both Antonín Dvořák and Bedřich Smetana in addition to collaborating frequently with her husband.
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.
Bedřich Smetana (] ; 2 March 1824 – 12 May 1884) was a Czech composer who pioneered the development of a musical style which became closely identified with his country's aspirations to independent statehood.
 He is thus widely regarded in his homeland as the father of Czech music.
 Internationally he is best known for his opera "The Bartered Bride" and for the symphonic cycle "Má vlast" ("My Homeland"), which portrays the history, legends and landscape of the composer's native land.
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.