Ksenia Erdeli was a Russian and Soviet harpist, composer, and teacher. She is regarded as a founder of the Soviet school of harp performance. She was born in the village of Myroliubovka, near Yelisavetgrad.
After graduating from the Smolny Institute for Noble Maidens in St. Petersburg in 1895, where she studied singing, piano, and choral conducting, Erdeli studied the harp with Ekaterina Walter-Kühne from 1891 to 1899. She played with the Italian Opera orchestra from 1895 to 1899 and began appearing as a soloist in 1899. She was a soloist with the Bolshoi Theatre orchestra from 1899 to 1907 and again from 1918 to 1938, and also performed with several other orchestras, including the State Symphony Orchestra of the USSR.
Erdeli gave the first performances of harp concertos dedicated to her by Nikolai Parfenov, Reinhold Glière, Vasily Tsybin, Sergei Vasilenko, and Anatol Kos-Anatolsky. She also gave the first performances of works for harp by César Cui, Alexander Grechaninov, Mikhail Ippolitov-Ivanov, Sergei Prokofiev, Lev Knipper, and Mikhail Koval. In Russia, she was the first to perform Maurice Ravel's Introduction and Allegro and Charles-Marie Widor's Chorale and Variations for harp and orchestra. Her programs often included her harp arrangements of works by Pyotr Tchaikovsky. She performed in ensembles with singers and instrumentalists, organized harp ensembles of up to 20 players, and initiated the formation of a professional harp quartet.
She taught at several institutions, including the St. Petersburg Conservatory and the Gnessin Musical Pedagogical Institute. She taught harp at the Moscow Conservatory from 1905 to 1907 and from 1918 until her death, becoming a professor in 1939. Her students included Vera Dulova, Elizaveta Kuzmicheva, and Olga Erdeli. Erdeli wrote arrangements, transcriptions, and editions for harp, as well as original works. Her compositions include Three Preludes (1948), Elegy in Memory of Mikhail Glinka (1950), Ukraine, a fantasy for harp (1952), and Forty Etudes (1961–1963).
Erdeli received the titles of Honored Artist of the Republic (1928), People's Artist of the Russian Soviet Federative Socialist Republic (1956), and People's Artist of the USSR (1966). Her memoir, The Harp in My Life, was published in 1967. She died in Moscow on May 27, 1971, and was buried at Novodevichy Cemetery.