However much Callas had grown fond of Onassis, she did not allow other people to interfere in her professional affairs. Until mid-1965, Maria Callas continued to give opera performances, albeit much less in number – despite Onassis’ advice to make films. In late 1960, she even returned to La Scala in Milan in the opera Poliuto (Gaetano Donizetti), though she did not sing the lead role.

On October 29, 1956, Maria Callas made her debut at the Metropolitan Opera in New York in the role of Norma from Vincenzo Bellini’s opera of the same name. It was not foreseen that the aria “Casta Diva” from Norma would find in Maria Callas one of its most famous interpreters: “Norma” was still quite unknown to the audience of the Met and many spectators were only coming to see Callas live for the first time.