Piano Concerto No.2 in C minor Opus 18 (2) Sergei Rachmaninov
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Scary Classical Music: Listen to 15 frightening pieces
Beginning life as a tone poem called St. John's Night on the bare Mountain, Mussorgsky's most famous work was made more famous by its revision from Rimsky-Korsakov, and then its inclusion in the soundtrack from Disney's Fantasia. Whatever incarnation it is, it's a frightening masterpiece.