Muzio Clementi was an Italian-born English composer, pianist, pedagogue, conductor, music publisher, editor, and piano manufacturer that lived in the Classical era. His piano etudes and sonatas developed the techniques of the early piano to such an extent that he was called ”the father of the piano”. Although he was born in Rome, he spent most of his life in England. Muzio wasn't born in a family of musicians, but his father, a noted silversmith, soon recognized his son's talents and arranged for private musical instruction with a relative, Antonio Baroni, the maestro din cappella at Saint Peter's Basilica.
When he was just 7 years old, Clementi began studies in figured bass with the organist Cordicelli, followed by voice lessons from Giuseppe Santarelli. At the age of 9 he was appointed as organist and by the age of 13 he had composed an oratorio, Martirio de' gloriosi santi Giuliano e Celso. He also received counterpoint lessons by Gaetano Carpani probably when he was 11 or 12 years old.
In 1766 Peter Beckford, a cousin of William Beckford, prevailed upon Clementi's father to allow him to take the boy to England, where he pursued a rigorous course of studies. In the same year, Muzio became organist of the parish San Lorenzo in Dámaso. For the next seven years Clementi lived, performed, and studied at the estate in Dorset. During this period, it appears, Clementi spent eight hours a day at the harpsichord, practicing the works of Johann Sebastian Bach, Carl Philipp Emanuel Bach, George Frideric Handel, Domenico Scarlatti, Alessandro Scarlatti and Bernardo Pasquini. His only compositions dated to this period are the Sonatas WO 13 and 14 and the Sei Sonate per clavicembalo o pianoforte, Op. 1.
His first public performance was in 1770 as an organist, the audience was pretty impressed with his playing, thus beginning one of the outstandingly successful concert pianist careers of the period. His success grew even bigger as he managed to establish himself as a composer and pianist following his spectacular debut in London (1773). Had Clementi matured anywhere else in Europe, he might have limited himself to the organ and harpsichord; but the piano was enormously popular in England, and Clementi furthered his career by capitalizing on the instrument's expanded capabilities.
In 1774, Clementi was freed from his obligations to Peter Beckford. During the winter of 1774–1775 he moved to London, making his first appearance as a harpsichordist in a benefit concert on April 3, 1775. He made several public appearances in London as a solo harpsichordist at benefit concerts for two local musicians, a singer and a harpist, and served as conductor (from the keyboard) at the King's Theater (Her Majesty's Theater), Haymarket, for at least part of this time. In 1780, he went on tour to the Continental capitals; in Vienna, Emperor Joseph II instigated a friendly musical duel between Clementi and Mozart. The composers were called upon to improvise and to perform selections from their own compositions. The Emperor diplomatically declared a tie.
In 1782 Clementi settled down in London where he divided his time between playing the piano, teaching and conducting. Among his students were: Johann Baptist Cramer, Ignaz Moscheles, Therese Jansen Bartolozzi, Ludwig Berger (who went on to teach Felix Mendelssohn), and John Field (who, in his turn, would become a major influence on Frédéric Chopin).
Toward the end of his life he traveled through Europe again and spent more and more time composing; during this time, he wrote several symphonies, but most have been lost. He is mainly remembered for his dozens of piano sonatas, and for his collection of studies, Gradus ad Parnassum (Steps Toward Parnassus), which has been the bane of piano students for two centuries and was parodied by Debussy in the opening movement of his Children's Corner. Clementi was the complete piano man, popularizing the instrument through his own performances, writing exercises to develop young pianists, writing sonatas for mature pianists to play, and manufacturing instruments for their use.
Here you can find a list of Muzio Clementi's compositions.