Sergei Prokofiev was a Russian composer, pianist, and conductor who is considered one of the major composers of the 20th century. He composed a wide range of works, including operas, symphonies, ballets, and film scores. Prokofiev's music is characterized by its use of sharp dissonance, rhythmic complexity, and a wide range of musical styles. He is best known for his ballets Romeo and Juliet and Cinderella, as well as his opera War and Peace.