Irmgard Seefried
She sang at the Salzburg Festival nearly every year and gave many recitals.  She appeared at the Royal Opera House of Covent Garden in London from 1947 to 1949, and also La Scala in Milan, Edinburgh Festival, etc. She sang at the  Metropolitan Opera in New York  during the 1953 -a1954 season the role of Susanna in Mozart's The Marriage of Figaro