Modest Mussorgsky

Many of his works were inspired by Russian history, Russian folklore, and other national themes. Such works include 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 posthumously come into their own in their original forms, and some of the original scores are now also available. Provided by Wikipedia