Serge Koussevitzky[1] (Russian: Сергей Александрович Кусевицкий; Sergey Aleksandrovich Kusevitsky) (July 26 [O.S. July 14] 1874 – June 4, 1951), was a Russian-born Jewish conductor, composer and double-bassist, known for his long tenure as music director of the Boston Symphony Orchestra from 1924 to 1949.