1973 he toured the US, appeared in Carmen and Turandot in Lisboa, held several recitals in the Far East before returning to New York and performances in La Boheme at the Met. Opera perfomances were now getting scant, and for the most part he sang in Turandot at the Met during 1974. 1975 he sang in Rome et Juliette and La Boheme at the Met, then Carmen and Turandot at the Arena di Verona in July and August and the he disappeared, after cancelling Norma during rehearsals at the Met in November. For a whole year Corelli did not perform and when he reappeared it was to be his very last performance in a complete opera: He sang the role of Rodolfo at the Torre de Lago under Nino Sanzogno, and Adriana Maliponte was his Mimi.

Corelli now officially retired from the stage, sensing that he was no longer able to to give the audience what they had become so accustomed to expect from him. Besides, he was losing interest in the stage and felt at last also relief: "I was a bundle of nerves," he later explained, making it clear that he did not miss the pressure of going on stage. Later his voice did perhaps regain its bloom, but Corelli had now grown comfortable off-stage and did not return, except for 5 last recitals in 1980-81, one in June 1980 in New Jersey, April 1981 in Newark, San Diego in May, Holmdel (New Jersey) in July and finally Stockholm in November, participating in a Gala Concert in honour of Swedish soprano Birgit Nilsson. Instead he turned to vocal teaching, together with his wife Loretta, and held occasional Master Classes.

Corelli's career was perhaps a strange one, starting with heavy repertory and continuing with lighter, contrary to most tenor careers. His incursions into the the lyric and romantic French repertory late '60s and early '70s, manifested through his recording for Decca of Gounoud's Faust in London during the summer of 1964, as well as his successful appearances at the Met in Gounod's "Romeo et Juliette (1967) and Massenet's "Werther" (1971), marked a path in a different direction that perhaps would have been logical for a voice of Corelli's calibre: His career would logically have gone along the line of heroic high roles, with Arnoldo of Rossini's Guglielmo Tell as the extreme, or dramatic low (baritonal) roles, particularly Otello. Instead he chose to scale down his huge voice and sing softly, much to Bing's delight, who paid duly to see Corelli sing in French. Corelli himself, however, was never truly convinced of his choice, these were difficult parts for him, and in the end prevented him from singing in particular two parts the opera world sadly missed out: Manon Lescaut and Otello.

His most cherished roles were Andrea Chenier, to many unsurpassed in this century, and probably his Calaf or Cavaradossi, which heroic spinto qualities matched those of Corelli perfectly. He was also an admired Manrico, first at La Scala, then the Met and the Wien Staatsoper. Himself, he often held Don José in Carmen to be one of his best roles, oddly enough he never performed this role at the Met.

Franco Corelli passed away in Milano, where he resided, on 29 October 2003 at 82. With his death one of the last great tenors of the 20th century is gone.