She began her career as a soubrette, and later moved into the light-lyric and lyric coloratura soprano repertoire and then the lighter Richard Strauss and Wagner operas.

[2] While she began her vocal lessons during this period as a mezzo-soprano, her voice developed a high upper register to the degree that her professional debut at age 23 was as the Queen of the Night in Mozart's The Magic Flute in Bratislava,[4] a role she revived in a 1963 recording conducted by Otto Klemperer.

In 1963, Herbert von Karajan invited her to join the Vienna State Opera, where she debuted as Barbarina in Mozart's The Marriage of Figaro.

[4] As a result of this vocal progression, Popp sang various roles in the same opera at different stages in her career, including Zdenka and Arabella in Richard Strauss's Arabella; Susanna and the Countess in Mozart's The Marriage of Figaro; Queen of the Night and Pamina in Mozart's The Magic Flute; Zerlina, Donna Elvira, and later Donna Anna in Mozart's Don Giovanni; Adele and Rosalinde in Johann Strauss II's Die Fledermaus; Ännchen and Agathe in Weber's Der Freischütz; and Sophie and the Marschallin in Richard Strauss's Der Rosenkavalier.

Recorded in 1982 in Vienna, published by Deutsche Grammophon Catalogue number 00440 073 4360, and in Die Fledermaus as Rosalinda (TDK).

[11] She was Sophie in Richard Strauss' Der Rosenkavalier DG 00440 073 4072 Carlos Kleiber conductor, Bayerisches Staatsorchester; Otto Schenk director, recorded 1979.

In 1993 she was the soprano soloist in Antonín Dvořák's Requiem with the Prague Symphony Orchestra conducted by Petr Altrichter on Arthaus music DVD 102145.