Clementi, Muzio, klay MEHN tee or kluh MEHN tee, MOO tsyoh (1752-1832), was an Italian composer best known for his piano music. Clementi was also a successful pianist, conductor, and manufacturer of pianos. His Gradus ad Parnassum (1817-1826) is a significant collection of 100 piano studies still used by students to develop their technique. Clementi's works also include more than 60 sonatas for piano or harpsichord, and about 40 sonatas for piano and other instruments. His compositions helped establish techniques for playing the piano, which was replacing the harpsichord as the most important keyboard instrument in the late 1700's.