Sergei Prokofiev (1891-1953) was a Russian composer, pianist, and conductor who later worked in the Soviet Union. A graduate of the Saint Petersburg Conservatory, Prokofiev initially made his name as an iconoclastic composer-pianist, achieving notoriety with a series of ferociously dissonant and virtuosic works for his instrument, including his first two piano concertos. As the creator of acknowledged masterpieces across numerous music genres, he is regarded as one of the major composers of the 20th century. His works include such widely heard pieces as the "March" from The Love for Three Oranges, the suite Lieutenant Kijé, the ballet Romeo and Juliet and Peter and the Wolf. Of the established forms and genres in which he worked, he created —excluding juvenilia— seven completed operas, seven symphonies, eight ballets, five piano concertos, two violin concertos, a cello concerto, a symphony-concerto for cello and orchestra, and nine completed piano sonatas.