Vancouver Opera, and the Opéra du Québec. He sang his last Rigoletto at the Opéra de Montréal in 1991. Throughout the 1970s he performed in various centres in the United States, including San Francisco (Luisa Miller), Philadelphia (I puritani), New Orleans (Manon), Baltimore (Tosca). He participated in concert version of rare operas with the American Opera Company with Eve Queler at Carnegie Hall, notably Gemma di Vergy and Parisina d'Este opposite Montserrat Caballé. In 1972 he sang the title role in the Opera Orchestra of New York's concert performance of Gioachino Rossini's William Tell with Klara Barlow as Mathilde. Quilico reached the Metropolitan Opera in February 1972 when he replaced at short notice the scheduled Golaud (Thomas Stewart) in Pelléas et Mélisande. His official debut there took place on January 1, 1973, as Germont. In 1987, Quilico appeared in Manon opposite his son Gino Quilico, also a baritone, a performance notable for being the first of a father and son in the same opera at the Met. During the Met's 1976 season, he debuted the role of the Bishop of Blois in their premiere of Massenet's Esclarmonde, repeating his earlier commercial recording of the same role from a year earlier. Quilico was also active as a teacher. He taught at the Faculty of Music of the University of Toronto, 1970–1987, at the McGill University in Montréal, 1987–1990, at Philadelphia's prestigious Academy of Vocal Arts, 1995–2000, and the Glenn Gould School, Toronto. In 2000 his widow Christina Petrowska Quilico created the Christina & Louis Awards Fund at the Ontario Arts Council which gives awards to emerging young singers. One of his pupils was bass John Dodington. With his wife, pianist Christina Petrowska-Quilico, , he embarked on a new phase of his career. The couple toured extensively in duo concerts and collaborated on his biography, Mr. Rigoletto: In Conversation with Louis Quilico and filmed a teaching video for York University. Quilico also continued his solo operatic career, performing Rigoletto for the last time in Ottawa in September 1994 with Opera Lyra (his 510th performance of the role). Quilico's appearances at the Metropolitan Opera during the 1990s included several of Pagliacci as well as Rigoletto, Tosca and Adriana Lecouvreur. He celebrated his 25th year at the Metropolitan Opera in 1996–97, and retired from that company in 1998. Analekta issued the Compact Disc entitled Mr. Rigoletto: My Life in Music (with pianist Christina Quilico)