Doch grausam zeigt sich der Waffen Los

Hermine Kittel (b. 2 December 1879, Vienna; d. 4 March 1948, Vienna), contralto.
Hermine Kittel was a member of the Vienna Court Opera (later the State Opera) from 1901 to 1931. She was married to the bass-baritone Alexander Haydter.
Mahler evidently held Hermine Kittel in high regard; she sang in a performance of his 2nd Symphony in Basel 1903, correspondence with Julius von Weis-Ostborn from July 1909 shows he recommended her to appear in a performance of Das klagende Lied in Graz, and a letter Mahler wrote to Bruno Walter in March 1910 tells us he chose her to perform at the premiere of his 8th Symphony in Munich, although she did not actually take part in the event.
She sang a variety of roles under Mahler at the Court Opera, including in the restaging of Richard Strauss' Feuersnot on 5 June 1905. She also played Marcellina on the new production of Rossini's Barber of Seville (alongside Kurz as Rosina and Haydter as Bartolo).

Elise Elizza (real name: Elisabeth Letztergroschen, b. 6 January 1870, Vienna; d. 3 June 1926, Vienna), soprano
Member of the Vienna Court Opera (Hofoper), 1895 – 1919
"... if Elizza, the goose, is stupidly knocking things over and Slezak is careless, conducting an ensemble properly is just impossible." (Gustav Mahler to Bruno Walter, 1901). Mahler made this comment despite being convinced of the soprano’s abilities. She sang at the premiere of his Das klagende Lied (Song of Lamentation) in Vienna in 1901, and he also tried to get her to perform in the premiere of his 8th Symphony in Munich in 1910. The quote above, taken from a letter, shines a light on Mahler’s uncompromising artistic demands; demands he expected to be met regardless of personal inclinations. The standards he set himself were every bit as high.