Leif Selim Segerstam ( LAYF, Swedish: ['l?jf 'se?g???am]; born 2 March 1944) is a Finnish conductor, composer, violinist, violist and pianist, especially known for writing 335 symphonies as of September 2019, along with other works in his extensive oeuvre.
Segerstam has conducted in a variety of orchestras since 1963, mostly American, Australian and European orchestras.
He is widely known through his recorded discography, which includes the complete symphonies of Blomdahl, Brahms, Mahler, Nielsen, and Sibelius, as well as many works by contemporary composers, such as the American composers John Corigliano and Christopher Rouse, the Finnish composer Einojuhani Rautavaara, Swedish composer Allan Pettersson and the Russian composers Alfred Schnittke and Alexander Scriabin.His contributions to the Finnish music scene and his vibrant personality have contributed to his fame.