His operatic debut came on 15 October 1914, when he played Enzo in Amilcare Ponchielli's La Gioconda in Rovigo, following which he was in great demand.

Gigli rose to true international prominence after the death of the great Italian tenor Enrico Caruso in 1921.

In fact, the comparison was not valid as Caruso had a bigger, darker, more heroic voice than Gigli's sizable yet honey-toned lyric instrument.

[citation needed] After leaving the Met, Gigli returned again to Italy, and sang in houses there, elsewhere in Europe, and in South America.

He was criticised for being a favourite singer of the Italian dictator Benito Mussolini, having recorded the Fascist anthem "Giovinezza" in 1937 (it is noticeably excluded from his "Edizione Integrale", released by EMI[4]).

Some notable appearances include 1936's Johannes Riemann-directed musical drama Ave Maria opposite actress Käthe von Nagy and Giuseppe Fatigati's 1943 drama I Pagliacci (English release title: Laugh Pagliacci), opposite Italian actress Alida Valli.

Before his retirement in 1955, Gigli undertook an exhausting world tour of farewell concerts, including performances at the Metropolitan Opera.

He said in his memoirs he married six months earlier than he actually did; this was to conceal the fact that his wife Costanza was pregnant before reaching the altar.

As he grew older, his voice developed some dramatic qualities, enabling him to sing heavier roles like Ràdames in Aida and Cavaradossi in Tosca.