Penderecki, Krzysztof (kshĭshˈtôf pändĕrĕtsˈkē) [key], 1933–, Polish composer. Penderecki studied at the Superior School of Music in Kraków. His music is characterized by unusual sonorities. He has devised his own system of notation to convey the effects desired. Penderecki's works include the Threnody in Memory of the Victims of Hiroshima (1960), a concerto for five-stringed violin (1967–68), Utrenja [morning prayer] (1970), and the St. Luke Passion (1963–66). From 1972 to 1987 he was rector of the Kraków conservatory.