Petrovich Mussorgsky (Moussorgsky) (March 21,1839 - March 28,1881), one of the Russian composers known as the Five, was an innovator of Russian music in the romantic period. He strove to achieve a uniquely Russian musical identity, often in deliberate defiance of the established conventions of Western music. Many of his works were inspired by Russian history, Russian folklore, and other nationalist themes, including the opera Boris Godunov, the orchestral tone poem Night on Bald Mountain, and the piano suite Pictures at an Exhibition. For many years Mussorgsky's works were mainly known in versions revised or completed by other composers. Many of his most important compositions have recently come into their own in their original forms, and some of the original scores are now also available.