During his stay in Frankfurt, Franz Xaver Mozart met with the most important personalities of the music-loving Frankfurt middle class.He was invited for dinner with Wilhelm Manskopf, played music at the home of the Passavant family and made trips to Offenbach to see the publisher, Johann André.He met the composer Franz Xaver Schnyder von Wartensee and the concertmaster Heinrich Hoffmann. In the theatre – it was still the beautiful Komödienhaus, in which his father had once given a concert – he saw the «Kalif von Bagdad» by Boieldieu and Süßmayr’s musical comedy «Soliman der Zweite oder Die drei Sultaninnen». The young Mozart was also the guest of the Neufville family. These were the descendants of those bankers, about whose bankruptcy in 1763, grandfather Leopold had reported.

Marianne Willemer played a not inconsiderable role in the Frankfurt music life. She had been the driving force behind the foundation of the Cäcilien-Verein and in this way also hoped to regain the interest of Johann Wolfgang Goethe in the cultural life of the city. In her letters to Goethe, she often speaks of Schelble and the work of the choir. Franz Xaver Mozart was the guest of the Willemers many times – probably in the house at the front of the Main and not in the Gerbermühle.

Johann Jakob von Willemer acquired the house «Zum Rothen Männchen» (the little red man) - originally «Mündelein» - in 1796. It stretched from 5 Alte Mainzer Gasse to 35 Mainkai. In the generously designed rooms of this stately house, the Willemer family could display a dignified luxury. The landing place for the ships was directly in front of its windows. One could see the large cranes, which Leopold Mozart had admired in 1763. They were in use well into the 19th century.

After «quite a boring» New Year’s Eve with the Bernard family and various goodbye visits, Franz Xaver Mozart left Frankfurt on the 3rd of January 1821. His conclusion (quotation on page 24) hints at the words of his father – it was «all a lot of boasting», what they said about the free cities. Nevertheless, because of the Cäcilien-Verein, the Frankfurt music life was in full bloom. At home, Franz Xaver founded his own Cäcilien-Verein, and Johann Nepomuk Schelble wrote in Mozart’s notebook:

«Take, dear friend, on your leaving, all my love and admiration with you! You were only given to me for a short time but what I received is everlasting. May heaven bring us together again soon and if it is possible, forever».