Sergei Vasilievich Rachmaninoff (Russian: Серге́й Васи́льевич Рахма́нинов, tr. Sergéj Vasíl'evič Rahmáninov; IPA: [sʲɪrˈɡʲej rɐxˈmanʲɪnəf]; 1 April [O.S. 20 March] 1873 – 28 March 1943) was a Russian pianist, composer, and conductor of the late-Romantic period, some of whose works are among the most popular in the classical repertoire. He is regarded as one of the major composers of the 20th century.