Teresa Stolz (born 2 June 1834, Elbekosteletz (Czech: Kostelec nad Labem), Bohemia – died 23 August 1902, Milan) was a Bohemian soprano, long resident in Italy, who was associated with significant premieres of the works of Giuseppe Verdi, and may have been his mistress. She has been described as “the Verdian dramatic soprano par excellence, powerful, passionate in utterance, but dignified in manner and secure in tone and control”.^[

https://en.wikipedia.org/wiki/Teresa_Stolz