 His most well-known opera is "La Gioconda" (1876), which his librettist Arrigo Boito adapted from the same play by Victor Hugo that had been previously set by Saverio Mercadante as "Il giuramento" in 1837 and Carlos Gomes as "Fosca" in 1873.The opera contains the famous ballet Dance of the Hours as the third act finale.It was first produced in 1876 and revised several times.