What uncompleted opera was composed by the composer of Il signor Fagotto?
Il signor Fagotto: Il signor Fagotto is a one-act opérette by Jacques Offenbach to a French libretto by Charles-Louis-Étienne Nuitter and Étienne Tréfeu, first performed in 1863. Jacques Offenbach: Jacques Offenbach (] ; ] ; 20 June 1819 – 5 October 1880) was a German-born French composer, cellist and impresario of the romantic period. Jacques Offenbach:  He is remembered for his nearly 100 operettas of the 1850s–1870s and his uncompleted opera "The Tales of Hoffmann".
"The Tales of Hoffmann"