Among all concertos, only two, No. 20 in D minor, K. 466, and No. 24 in C minor, K. 491, are in minor keys. The concertos in major keys were undervalued in the 19th century. Clara Schumann's concert repertoire contained only the D minor, the C minor, and No. 10 for two pianos in E major, K. 365, which she first performed in concert in 1857, 1863, and 1883 respectively.Litzmann, Berthold, Clara Schumann: An Artist's Life based on diaries and letters, McMillan, London, 1913, vol. 2 pp. 442–52. Peter GutmannPeter Gutmann calls the D-minor concerto "the most historically popular and influential" of all the concertos. He writes that "overtly dark, dramatic and impassioned", it was an antecedent of Beethoven and "appealed directly to the romanticized taste of the 19th century." Beethoven (WoO 58), Brahms (WoO 16), and Clara Schumann wrote cadenzas for it.
