Ordassy emigrated to the U.S. and won a scholarship and a Met contract on the 1956 "Auditions of the Air" radio series, according to Opera News. She made her Met debut as Gerhilde, one of the Valkyries, in Die Walk‹re in 1957.
She sang Alisa in 118 Met Lucia di Lammermoors and 109 Giovannas in Rigoletto. Other frequent Met roles included Ines in Il trovatore (the part in which she made her final appearance wih the company in 1977); Cura in La forza del destino; the Priestess in Aida and Clotilde in Norma.