[4] Influenced primarily by the films of Mario Lanza and learning from recordings of many historic tenors, he then switched to opera, but remained largely self-taught.

After winning the Luciano Pavarotti International Voice Competition, an initiative backed by the Italian Ministry of Cultural Heritage and Activities, that started in Modena in 1988, Alagna made his professional debut as Alfredo Germont in La traviata with the Glyndebourne touring company.

The tenor's reaction to his public criticism was denounced as immature and unprofessional by La Scala management and Zeffirelli, who said, "A professional should never behave in this way.

"[10] The role of Radames was taken over successfully for the rest of the performance by his understudy Antonello Palombi, who entered on stage wearing jeans and a black shirt.

[12] The 15 December performance of Roméo et Juliette starring Alagna and Netrebko was broadcast by the Met into 447 theatres worldwide in high definition and seen by about 97,000 people.

[13] In recent years, Alagna has been an advocate of restoring to prominence neglected French operas – Alfano's Cyrano de Bergerac, Massenet's Le jongleur de Notre-Dame, Lalo's Fiesque, and new works – Vladimir Cosma's Marius et Fanny and his brother David Alagna's Le dernier jour d'un condamné.

Alagna was scheduled to make his debut at the Bayreuth Festival on opening day, 25 July 2018, in the title role of a new production of Richard Wagner's Lohengrin.