During a stage career spanning 40 years, he created many leading baritone roles, including Zurga in Bizet's Les pêcheurs de perles and Ourrias in Gounod's Mireille.

However, his family were too poor to afford any kind of music lessons for him, and at the age of sixteen he left home to earn a living as a street singer, working his way on foot to Bordeaux and then Nantes.

[3] At Nantes, he was taken on as a chorister at the opera house during the 1842-1843 season and before his 17th birthday achieved local success when he stepped in at the last minute to sing the role of Max in a production of Adam's Le chalet.

This was followed by appearances beginning on 24 December in the title role of Verdi's Rigoletto, a new production which was highly successful and established Ismaël as one of the leading singers in the French capital.

He then sang at the Opéra de Marseille before returning to Paris in 1871 to join the Opéra-Comique at the Salle Favart, where he sang in the premieres of several more operas and operettas including Offenbach's Fantasio and Delibes' Le roi l'a dit as well as the company's first performances of Gounod's Roméo et Juliette (as Frère Laurent) and Le médecin malgré lui (as Sganarelle).

[11] He was appointed Professor of Lyric Declamation (Opera) at the Paris Conservatoire on 1 February 1874, but on 23 December 1876 he was abruptly dismissed from his post without explanation.

Amongst his performances at the Théâtre du Casino in Monte Carlo was the title role in Planquette's Le chevalier Gaston for its world premiere in 1879.

[notes 1] In order to marry one of his students, Ismael requested a divorce as soon as she returned to the jurisdiction of French law ( she could not be served by judicial authorities as she was continuing her career in Belgium).

They were officially divorced in 1885 after years of living apart,[16] and shortly thereafter he married Marie Garcin (1858–1946), a young opera singer who had been one of his pupils.