[1] Born in Hopewell, New York, Walker had her initial musical training at her church in her native town where she sang in the choir and began performing solos at the age of 14.
She sang several more roles at Covent Garden in 1900–1901, all of them from the Wagnerian repertoire, including Erda in Siegfried, Fricka in both Die Walküre and Das Rheingold, Ortrud in Lohengrin, and Waltraute in Götterdämmerung.
Having broken her contract with the influential Vienna opera house, she found it impossible to gain a permanent position with another German or Austrian theatre under such circumstances.
She made her debut at the Metropolitan Opera House on November 30, 1903 as Amneris to the Aida of Johanna Gadski and the Radamès of Enrico Caruso.
Her final and 108th performance with the Metropolitan Opera was in the title role of Karl Goldmark's Die Königin von Saba for an out of town engagement in San Francisco on April 16, 1906.
[1][5] While on contract with the Met, Walker began adding soprano roles to her repertoire, beginning with Brünnhilde in Die Walküre which she first performed at the Metropolitan Opera House in December 1905.
Walker had already been performing periodically as a guest artist with the Hamburg State Opera (HSO) since 1903, and upon her return to Europe she signed a contract with that company.
[1] She returned to the Royal Opera House in 1910 to portray the title role in the critically acclaimed UK premiere of Richard Strauss' Elektra under the baton of Sir Thomas Beecham,[4][6] and to sing the part of Thirza in Ethel Smyth's The Wreckers.
Kaiser Wilhelm II was in attendance and, impressed with her performance, the emperor made a point of having Walker presented to him.