Elisabeth Rethberg, born Lisbeth Sattler in Schwartzenberg, was one of the finest sopranos of the period. She studied at Dresden and made her debut with the Dresden Opera in 1915 and remained there seven years. In 1922, she made her Metropolitan debut as Aida and reigned as a leading soprano there for 21 consecutive seasons. During those years she also returned regularly to Dresden, and performed at Covent Garden and at the Salzburg Festivals.
I first encountered Rethberg's voice in a Victor recording of the Act 3 trio from I Lombardi with Gigli and Pinza. Rethberg's voice was absolutely thrilling. Unfortunately, the recording suffers from rather severe inner groove distortion (someday I'll get around to writing an article on the history of the phonograph and explain that). Although a member of the legendary "German wing" at the Met, she also performed, with great success, the standard Italian and French roles. An opera afficionado (can't remember which one) noted that Rethberg was one of those rare sopranos who could sing anything. Indeed, her repertory included Wagner, Verdi and Mozart. Desmond Shawe-Taylor notes that "her beautiful lirico spinto soprano was perfectly equalized between the registers, and a combination of natural musicianship and sound training enabled her to maintain an unusually even legato in the most difficult passages."
This recording is on the Brunswick label (acoustic, I think; definitely before 1930) and is technically not very good. As I have said before, there was no tape, no tweaking, no fixing. This recording sounds as if Rethberg was too close to the horn, but I think it is still quite electrifying.