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
Wolfgang Amadeus Mozart and Prague pointed out how precarious opera production was in the city throughout the eighteenth century. Indeed, productions of Italian opera in Prague ceased again already in 1789, not to re-appear again until 1791, due to the departure of the impresario Domenico Guardasoni and the death of the impresario Pasquale Bondini. Another possible reason why Mozart didn't stay is given by Volkmar Braunbehrens, citing Schenk: the death in Vienna in November 1787 of Gluck, whose post in the Imperial musical establishment Mozart sought (and ultimately got, though at a much lower salary); Mozart needed to return home to lobby for the position.