Clementi & Co. 1798-1830

Clementi pianos were built in London in the early 1800s by Italian-born composer, conductor, and pianist Muzio Clementi. These pianos are smaller and have fewer octaves than modern pianos, with Clementi pianos typically having a six-octave keyboard, and modern pianos having seven and one-half octaves. The musical sound of a Clementi piano is somewhat in between a harpsichord and grand piano.

When Clementi got into the piano-building business, he was already famous. Born in Rome in 1752, Clementi — a prodigy — was taken to England at the age of 14 by Peter Beckford, an aristocrat who struck a deal with Clementi’s father to have the boy provide music at his estate. Beckford proved more interested in hunting than music; left to his own devices, Clementi practiced for hours a day, building up an unrivaled technique. Clementi was soon touring Europe; on one of those concert tours, Clementi famously participated in a pianistic cutting contest with Mozart (who found Clementi’s playing impressive but devoid of emotion).

Back home in England, Clementi’s celebrity as a performer did not translate into social status. The British path to respectability was business, in which Clementi proved fluent. His start was inauspicious: He invested in a London company, Longman and Broderip, which soon went bankrupt. But John Longman, Clementi, and others formed a new company; partners came and went, but Clementi remained, and Clementi & Co. prospered, as publisher (Clementi’s large corpus of educational music — such piano-lesson staples as his “Gradus ad Parnassum” and Sonatinas — diluted his reputation as a composer, but sold handsomely) and piano manufacturer. (“Playing Clementi on a Piano Built by Clementi – the Boston Globe”  2016)

The predecessor of Clementi & Co. was Longman & Broderip, the instrument manufacturer and music publisher. They were known primarily for producing harpsichords and pianofortes. When John Longman joined his company together with Clementi, Clementi was already a famous composer and educator of talented pianists. Clementi was involved in sales and marketing of the pianos, but never actively participated in physically producing them.

Clementi & Co. Pianos

The grand pianos were apparently produced at a relatively constant level in the years 1803–1809, around 60–70 pianos per year. During 1810–1811 a sharp increase took place, a potential consequence of the new six octave instruments being introduced with their more modern appearance, such as turned, screwed-in legs instead of the earlier trestle stand. Clementi & Co ought to have started producing a six octave compass in 1809 rather simultaneously for squares and grands.

Clementi was highly successful at marketing the early pianoforte internationally. In particular, his company was able to push forward developments with tone improvement. 

Clementi preferred a light, transparent action on his pianos, but his firm’s most noteworthy innovation was a “harmonic swell,” developed by Clementi’s partner, William Frederick Collard, with which extra string lengths could be undamped, lending a glow of sympathetic resonance to the main sound — anticipating the sustain-pedal-fueled richness that would become part and parcel of Romantic piano technique. Clementi’s pianos embody both the era’s musical evolution and the highly developed technique and taste of Clementi himself, squaring a tendency toward bigger, louder instruments with the older Classical virtues of clarity and clean articulation.  (“Playing Clementi on a Piano Built by Clementi – the Boston Globe”  2016)

In 1784, Clementi spent a summer in Bern, where he where he is believed to have met Christian Müller and seen one of Müller’s instruments with a “harmonic swell”. Clementi used this system in his own instruments with the name: “Harmonic Swell – Bridge of Reverberation” in 1821 [5]. Because Müller had passed by 1821, Clementi was allowed to completely reinvent the system without any patent rights.