He is most famous for the libretto of Die Fledermaus, Johann Strauss II's most famous operetta. He co-wrote the libretto without having met top-billed librettist Karl Haffner, who constructed the new story based on a play by Henri Meilhac and Ludovic Halévy, which was considered too shocking to perform outside Paris. Genée, however, wrote the operetta's actual text and drew nothing from Haffner beyond the names of the characters.[2] One of his best-known works was the libretto of Carl Millöcker's operetta Der Bettelstudent, which he co-wrote with Friedrich Zell (the pseudonym of Camillo Walzel). He also wrote the libretto to Ella Adayevskaya's 1877 opera Zarya. In 1857 he was conductor of the Philharmonic Orchestra Mainz.
