Born on 22 April 1935, in Crescentino,[1] Province of Vercelli, Italy, Cossotto attended the Turin Academy of Music and studied with Mercedes Llopart.
She made her operatic debut as Sister Matilde in the world premiere of Poulenc's Dialogues of the Carmelites in 1957 at La Scala in Milan.
She also portrayed Carmen, Mozart's Cherubino, Urbain in Meyerbeer's Les Huguenots, Bellini's Romeo and Marfa in Khovantschina.
She [Cossotto] won plaudits in the annals of operatic history for her wonderful vocal timbre, her perfect singing technique, and the ease with which she could master different registers.
She sang Adalgisa next to the Normas of Callas, Joan Sutherland, Montserrat Caballé, Leyla Gencer, and Elinor Ross[2] Her repertory at the Met included Amneris, Eboli, Adalgisa, Santuzza, Azucena, Dalila, Carmen (only on tour and in outdoor park concerts), Principessa di Bouillon (Adriana Lecouvreur) and Mistress Quickly (which she added in 1985, singing with Giuseppe Taddei as Falstaff).