One of the three potent Wagnerian heroic sopranos born within a half year of each other, Gertrud Grob-Prandl, according to numerous colleagues, outshone both Astrid Varney and Birgit Nilsson in sheer amplitude. Soprano Irmgard Seefried swore that "the walls shook" when Grob-Prandl sang Turandot, and indeed, the great-voiced soprano achieved celebrity in Italy surpassing even that accorded her in her native Austria. Grob-Prandl's voice was not merely immense, it was firmly knit and true, with a fast vibrato that avoided any taint of the unwieldy. If her passagework in Mozart was slightly labored, her dramatic roles were all sung with lyricism as well as power. Urged by her father to acquire a profession, Grob-Prandl chose to pursue a diploma in piano at the Vienna Conservatory in order to become a teacher. An amateur performance of Beethoven's Symphony No. 9 brought auditions to fill out the chorus and when the professors heard the size of her voice, the decision was immediately made to enroll her in a singing class. Working mostly with Papier Singer-Burian, Grob-Prandl found herself engaged by the Vienna Volksoper even before the end of her four-year academic program. After her 1939 debut there as Santuzza, she was plunged into the hochdramatisch repertory, including Leonore, Elisabeth, Ariadne (heard by Strauss), and a lengthy list of large Italian roles, all sung in German. A hoped-for production of Strauss' Die Ägyptische Helena under the composer's baton came to naught due to the widening war in Europe. In January 1944, Grob-Prandl joined the Vienna Staatsoper where she sang for nearly three decades, although from 1945 to 1947, she was the leading dramatic soprano in Zürich. With the Vienna Staatsoper destroyed by Allied bombs during WWII and so many sets and costumes reduced to powder, those operas for which a production could be pulled together were the ones to be heard following the cessation of hostilities. Thus, Grob-Prandl was heard in some 35 performances of Die fledermaus as Rosalinde, a luxury seldom thereafter accorded her. In 1949, she made an appearance at Salzburg in the important but rather brief role of the First Lady. Grob-Prandl's first Walküre Brünnhilde was sung in 1949 with Clemens Krauss as her conductor. With conductor Rudolf Moralt, she undertook the Siegfried and Götterdämmerung Brünnhildes that same year, finding in them both strength and lyric expression. The role of Isolde was introduced with the Vienna Staatsoper shortly before the company took its production from the Theater an der Wien to Brussels. Grob-Prandl's enormous success there resulted in her being made a Kammersängerin when the company returned to Vienna. In Italy, the soprano relished working with Victor de Sabata, whose Tristan und Isolde she found graceful and poetic. Grob-Prandl appeared at Covent Garden in 1951 to sing Turandot in English with Sir John Barbirolli conducting. Her mastery of Turandot, in fact, most endeared her to Italian audiences who appreciated her stentorian sound and fiery top notes. Bayreuth eluded her, as did America, except for the 1953 season in San Francisco when she appeared as the Walküre Brünnhilde, Isolde, and Amelia. With Nilsson later dominating the big roles in America, there was little call for Grob-Prandl's services. Aside from regular appearances in Italy and occasional guest performances in other European houses, Grob-Prandl primarily sang at her home theater in Vienna, retiring in 1972 while her voice was still in its prime.