 In 1953, Nelli debuted at the Metropolitan Opera, with which she appeared until 1961.She was seen in "Aida" (conducted by Renato Cellini), "La forza del destino", "Il trovatore", "Cavalleria rusticana", "Andrea Chénier", "Un ballo in maschera" (with Marian Anderson, conducted by Dimitri Mitropoulos) and Mozart's "Don Giovanni" (as Donna Anna, her only Mozart role).With the Met, she toured to Boston, Philadelphia, Cleveland, Atlanta, Dallas, Toronto and Minneapolis.