Among the many roles she has portrayed there are Adele in Die Fledermaus, Almirena in Rinaldo, Amor in Gluck’s Orphée et Eurydice with conductor William Christie, Celia in Mozart’s Lucio Silla with conductor Nikolaus Harnoncourt, Echo in Ariadne auf Naxos, Lenio in The Greek Passion, Marzeline in Fidelio, Pamina in The Magic Flute, the Sand Man in Hänsel und Gretel, Serpetta in La finta giardiniera, the Shepherd in Richard Wagner’s Tannhäuser under the baton of Franz Welser-Möst, and Susanna in Le nozze di Figaro among others.
Scheduled upcoming performances for Janková include Zerlina in Don Giovanni (September 2009), Angelica in Orlando (November 2009-January 2010), Despina in Così fan tutte (December 2009), and Servilia in La clemenza di Tito (March 2010).
With the Prague State Opera she has sung Despina for conductor Gustav Kuhn, Sofia in Rossini’s Il Signor Bruschino, and Zerlina under the direction of Katherina Thalbach.
At the Grand Théâtre de Genève she has appeared in the title role of Janáček’s The Cunning Little Vixen and as both Drusilla and Fortuna in Monteverdi’s L'incoronazione di Poppea.
She also been active as an oratorio soloist, notably singing in Mendehlssohn's Elijah with the Israel Philharmonic Orchestra under conductor Wolfgang Sawallisch.