La chanson de Fortunio (The Song of Fortunio) is a short opéra-comique in one act by Jacques Offenbach with a French libretto by Ludovic Halévy and Hector Crémieux. The music was composed within a week, with a further week being spent in preparations for the production. Its success was welcome after the failure of Barkouf a fortnight earlier.
Taken as a whole, this operetta has never really formed part of what may be termed the standard repertoire, but despite this, and especially during the period prior to the First World War, the title song remained extremely popular as a recital item, and indeed the writer of Offenbach's obituary in The Times considered the song itself to be one of his best compositions along with Orpheus in the Underworld and La Grande-Duchesse de Gérolstein – with La belle Hélène following behind these "at some distance".
Offenbach had composed music for the song of Fortunio in act 2, scene 3, of Le Chandelier by Alfred de Musset for a revival of the play in 1850 at the Comédie-Française and this was published (by Heugel) as part of Offenbach's collection of songs Les voix mystérieuses in 1853, and taken up enthusiastically by the tenor Gustave-Hippolyte Roger in his concerts. The librettists based their one-act La chanson de Fortunio around this song – with the story as a sort of sequel to the original play, the melody of the song being heard in the overture.
Messager composed an opera Fortunio (1907) based on the Musset play; Fortunio's song from that work was also set in Russian by Tchaikovsky as the first of his six Romances, Op. 28.