Eventually, her music teacher at the Wüllenweber-Gymnasium in Bergneustadt, August Wilhelm Welp, noticed her considerable talent and recommended that she be professionally educated in singing.
[3] Peter Jonas, director of the Bavarian State Opera, who was in the jury, recognised her talent and engaged her in the role of Agathe in Der Freischütz.
She became a frequent guest singer with the company, starring in roles such as Countess Almaviva (The Marriage of Figaro), Fiordiligi (Così fan tutte), Mimì (La bohème), and among others she later took up.
[4][5] In February 2002, she sang her first Wagnerian role, Freia in Das Rheingold, in the premiere of Herbert Wernicke's new production at the Bavarian State Opera.
She performed in The Magic Flute as the First Lady at the Salzburg Festival, and later at the Hamburg State Opera, as Eva in Die Meistersinger von Nürnberg in Peter Konwitschny's controversial new production.
[7] In 2003/04, Harteros made her New York Metropolitan Opera debut with Countess Almaviva, and also sang Donna Anna in Don Giovanni in the same season.
[17] Withdrawing from the planned debuting performances as the Marschallin in Strauss' Der Rosenkavalier in San Diego,[18] she assumed the role in Munich and then in Vienna later in the year.
[28] Following her Tosca performance on 3 November 2019 at the Bavarian State Opera, celebrating her 20th anniversary since her debut with the company, she was awarded the Meistersinger-Medaille in honour of her artistic contribution.