Noctave
Born in Russia in 1873, Rachmaninoff studied at the Moscow Conservatory and pursued careers as both composer and pianist. After the 1917 revolution he left Russia and lived mostly in the United States, where he died in 1943. For the piano he wrote four concertos, the Rhapsody on a Theme of Paganini, sonatas, Études-tableaux and twenty-four preludes, one in each key. The Prelude in C-sharp minor is the first of them, written in 1892.
It is the only Rachmaninoff piece in the catalogue. It opens with three notes in octaves, A, G-sharp, C-sharp, which return throughout the piece. Full chords and octaves in both hands are constant, across almost the whole keyboard: let the weight of your arm make the sound rather than striking. The middle section, Agitato, is faster; at the end, the four staves of the score have been brought back to two hands.