"Rhapsody on a Theme of Paganini" is a composition by Sergei Rachmaninoff, written in 1934. It is a set of variations for piano and orchestra based on a theme by the Italian violinist Niccolò Paganini. The piece is known for its lyrical melodies and virtuosic piano passages, showcasing the pianist's technical skill. The work consists of 24 variations, with the 18th variation being particularly famous for its romantic and expressive qualities. Rachmaninoff's composition blends elements of classical music with rich harmonies, making it a popular choice in concert halls and a favorite among both musicians and audiences.