In the 1960s , Schwarzkopf concentrated nearly exclusively on five operatic roles : Donna Elvira in `` Don Giovanni '' , Countess Almaviva in `` The Marriage of Figaro '' , Fiordiligi in `` Così fan tutte '' , Countess Madeleine in Strauss 's `` Capriccio '' , and the Marschallin .
In the 1960s , when Schwarzkopf sang in operas she nearly always sang one of her five favourite operatic roles : Donna Elvira in Mozart 's `` Don Giovanni '' , Countess Almaviva in `` The Marriage of Figaro '' , Fiordiligi in `` Così fan tutte '' , Countess Madeleine in Strauss 's `` Capriccio '' , and the Marschallin in `` Der Rosenkavalier '' .