Question: How long was the concert career of the woman that is speculated to be the frustrated love inspiration of Brahms' Liebeslieder Walzer, Op. 52?
Sentence (from "Liebeslieder Walzer, Op. 52 (Brahms)"): While there is no concrete record indicating the exact inspiration for the Waltzes, there is speculation that Brahms' motivation for the songs was his frustrated love for pianist Clara Schumann, composer Robert Schumann's wife.
Relevant evidence: Yes