Sergey Fyodorovich Letov (Russian: Серге́й Фё́дорович Ле́тов, born September 24, 1956), is a Russian musician and composer, known for his improvisational style. He is the founder of the recording label Pentagram. He has collaborated with numerous jazz, avant-garde, modern classical, rock and electronic music artists, including his younger brother Yegor Letov, composer Sergey Kuryokhin, and cult Soviet art punk band DK. Letov has written music for movies and plays, collaborating with Russian, Italian and Austrian theatres, the German non-profit cultural association Goethe-Institut, and the Moscow Institute of Journalism and Literature.