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
Vienna Mozart Orchestra world-famous opera houses, principally from the Vienna State Opera and the Vienna Volksoper, perform with the Vienna Mozart Orchestra. Best-known and most popular is the concert series “Vienna Mozart Concerts in historical costumes”, performed every year from May until the end of October, four times a week. An ideal background for these concerts is provided by the Golden Hall of the Musikverein, the Vienna State Opera and by the Great Hall of the Konzerthaus (each about 40 concerts a year). As a co-production with Klangbogen Wien within the framework of the Millennium celebrations in 1996, ten open-air concerts were performed