Leif Selim Segerstam was a Finnish conductor, composer, violinist, violist, and pianist, especially known for writing over 300 symphonies, along with other works in his extensive oeuvre.
Segerstam conducted a variety of orchestras from 1963, in Europe, the Americas and Australia. He was conductor at the Finnish National Opera, the Royal Swedish Opera and Deutsche Oper Berlin, and was chief conductor of the ORF Symphony Orchestra, Staatsphilharmonie Rheinland-Pfalz, the Danish National Radio Symphony, Helsinki Philharmonic Orchestra and the Turku Philharmonic Orchestra. He is widely known through his recordings, including the complete symphonies of Blomdahl, Brahms, Mahler, Nielsen, and Sibelius, as well as many works by contemporary composers. He is remembered for his contributions to the Finnish music scene, and his vibrant personality.
He taught as professor of orchestra conducting at the Sibelius Academy in Helsinki.