Abraham Zevi Idelsohn (Hebrew: אַבְרָהָם צְבִי אידלסון Avrohom Tzvi Idelsohn in Ashkenazi Hebrew; middle name also rendered Tzvi, Zvi, Zwi, or Zebi; June 11, 1882[1] – August 14, 1938) was a prominent Jewish ethnomusicologist and composer, who conducted several comprehensive studies of Jewish music around the world.

Idelsohn was born on 11 June 1882 to Jewish parents in Feliksberg, a fisher hamlet in present-day Ventspils, Latvia (then part of the Russian Empire).

There, due to the efforts of Philip Klein, Idelsohn's father was appointed overseer of kosher meat in a non-Jewish butchery.

In June 1931, the South African Jewish Religious Union for Liberal Judaism was established with Jerry as honorary secretary, and a wide media campaign was launched.

[5] Idelsohn is generally acknowledged as the “father” of modern Jewish musicology, despite his publishing starting after that of Angie Irma Cohon.

He found that these motifs fell into three distinct tonal centers, which corresponded to the Dorian, Phrygian, and Lydian modes of the ancient Greeks.

"[7][8] His works include the monumental Thesaurus of Hebrew Oriental Melodies (10 volumes, 1914–1932), Jewish Music (1929), and a collaboration with Cohon on Harvest Festivals, A Children’s Succoth Celebration.