Question: What nationality was the composer of the symphonic poem Prince Rostislav ? 
Sentence (from "Sergei Rachmaninoff"): Sergei Vasilievich Rachmaninoff (Russian: Серге́й Васи́льевич Рахма́нинов , "Sergey Vasilyevich Rakhmaninov"; ] ; 1 April [O.S. 20 March] 1873 28 March 1943) was a Russian virtuoso pianist, composer, and conductor of the late-Romantic period, some of whose works are among the most popular in the romantic repertoire.
Relevant evidence: Yes