Muzio Clementi was born in Rome in 1752, the first of seven children, to Nicolò Clementi, a highly respected silversmith and Roman by heritage, and Magdalena Kaiser, who was Swiss. His musical talent became clear at an early age: by age seven he was in musical instruction, and was such a good student that by age nine he gained a position as a church organist.
In 1766, Sir Peter Beckford (1740-1811), a wealthy Englishman and cousin of the eccentric William Beckford, took an interest in the boy's musical talent, and struck a deal with Nicolò to take Muzio to his estate of Steepleton Iwerne, just north of Blandford Forum in Dorset, England — where Beckford agreed to provide quarterly payments to sponsor Muzio's musical education. In return for this education, he was expected to provide musical entertainment at the estate. It was here that he spent the next seven years in devoted study and practice at the harpsichord. His compositions from this early period, however, are few, and they have almost all been lost.
In 1770, Clementi made his first public performance as a pianist. The audience was very impressed with his playing, beginning what at the time was one of the most successful concert pianist careers in history. In 1774, Clementi was freed from his obligations to Peter Beckford, and he moved to London, where among other accomplishments he made several public appearances as a solo harpsichordist at benefit concerts for a singer and a harpist, and served as "conductor" — from the keyboard — at the King's Theatre, Haymarket for at least part of this period. His popularity grew in 1779 and 1780, due at least in part to the popularity of his newly-published Opus 2 Sonatas. His fame and popularity rose quickly, and he was considered by many in musical circles to be the greatest piano virtuoso in the world.
Clementi started a European tour in 1781, when he travelled to France, Germany, and Austria. In Vienna, Clementi agreed with Emperor Joseph II to enter a musical duel with Wolfgang Amadeus Mozart for the entertainment of the Emperor and his guests. Each performer was called upon to improvise and perform selections from his own compositions. The ability of both these composer-virtuosi was so great that the Emperor was forced to declare a tie.
On January 12, 1782, Mozart wrote to his father: "Clementi never played well, as far as execution with the right hand goes. His greatest strength lies in his passages in 3rds. Apart from that, he has not a kreuzer 's worth of taste or feeling — in short he is a mere mechanicus" (that is, Latin for automaton or robot). In a subsequent letter, he even went so far as to say "Clementi is a charlatan, like all Italians. He marks a piece presto but plays only allegro." Clementi's impressions of Mozart, by contrast, were all rather enthusiastically positive. But the main theme of Clementi's B-Flat Major sonata captured Mozart's imagination, and ten years later he used it in the overture to his opera Die Zauberflöte (The Magic Flute). This so embittered Clementi that every time this sonata was published, he made certain that it included a note explaining that it had been written ten years before Mozart began writing Zauberflöte.
A likely reason that these later works were not published in Clementi's lifetime is that he kept revising and tinkering with them. Starting in 1782, and for the next twenty years Clementi stayed in England playing the piano, conducting, and teaching. Two of his students attained a fair amount of fame for themselves: Johann Baptist Cramer and John Field (who, in his turn, would become a major influence on Frédéric Chopin). Clementi also began manufacturing pianos, but in 1807 his factory was destroyed by a fire. That same year, Clementi struck a deal with Ludwig van Beethoven, one of his greatest admirers, that gave him full publishing rights to all of Beethoven's music. His stature in music history as an editor and interpreter of Beethoven's music is certainly not less than as being a composer himself (although also criticised for some less docile editorial work, e.g., making harmonic "corrections" to some of Beethoven's music). That Beethoven in his later life started to compose (mostly chamber music) specifically for the British market might have been related to the fact that his publisher was based there. In 1810, Clementi ceased his concerts to devote all of his time to composition and piano making. On January 24, 1813, in London, Clementi, who with a group of professional musicians, banded together to put matters right, founded the "Philharmonic Society of London" which became the Royal Philharmonic Society in 1912. In 1830 he moved to live outside Lichfield and then spent his final, less exciting years in Evesham, where he died at age eighty. He was buried at Westminster Abbey. He had been married three times but that's not why he died.
