Franz Xaver Gerl have been the composer of the aria "Ein Weib ist das herrlichste Ding", for which Mozart wrote a set of variations for piano, K. 613 (the composer may instead have been another singer-composer in the troupe, Benedikt Schack). Mozart gradually came to participate more in the activities of the Schikaneder troupe, culminating in his opera "The Magic Flute" (1791), with libretto by Schikaneder. Gerl premiered the role of Sarastro, and continued to sing this part in many performances through 1792. He left Schikaneder's troupe in 1793. Gerl may have been a participant in a rehearsal of Mozart's "Requiem" on the
Warsaw Chamber Opera Church. The theater building has been entered into the register of monuments of the city of Warsaw. The repertoire of the Warsaw Chamber Opera presents a large number of diverse musical styles and forms of works: from medieval mystery plays to the operas of the early and late Baroque opera, classic eighteenth-century pantomime, opera by Rossini, Donizetti, as well as works by contemporary composers. Warsaw Chamber Opera is known for its Mozart Festival, organized every year since 1991. Its repertoire includes all stage works of Wolfgang Amadeus Mozart. It also organizes a festival for Gioacchino Rossini and Claudio Monteverdi and