Krzysztof Penderecki was a Polish composer of 20th century classical music, a period characterized by the use of dissonance.
Outside of the classical music domain his music has been popular in horror films. The piece Polymorphia (1962) for example, is used in The Exorcist (1973) and in The Shining (1980).
And then there is his opera based on the book The Devils of Loudun (1952) by Aldous Huxley. The story of the Loudun possessions is highly remarkable and any occasion to bring it to your attention, shall be grasped.