CLAVICHORD or CLARICHORD, a mediaeval stringed keyboard instrument, a forerunner of the pianoforte (q.v.), its strings being set in vibration by a blow from a brass tangent instead of a hammer as in the modern instrument.
The clavichord, derived from the dulcimer by the addition of a keyboard, has a long history, being mentioned as early as 1404 in Eberhard Cersne's Rules of the Minnesingers.
There were two kinds of clavichords—the fretted or gebunden and the fret-free or bund-frei. The term "fretted" was applied to those clavichords which, instead of being provided with a string or set of strings in unison for each note, had one set of strings acting for three or four notes, the arms of the keys being twisted in order to bring the contact of the tangent into the acoustically cor rect position under the string. The "fret-free" were chromati cally-scaled instruments.
The first bund-frei clavichord is attributed to Daniel Faber of Crailsheim in Saxony about '720. This important change in con struction increased the size of the instrument, each pair of unison strings requiring a key and tan gent of its own, and led to the in troduction of the system of tun ing by equal temperament upheld by J. S. Bach and practically illustrated by him in his im mortal "Wohltemperirtes Clav ier" ("Well-tempered Clavier") written expressly to encourage its adoption.
The tone of the clavichord, ex tremely sweet and delicate, was characterized by a tremulous hes itancy, which formed its great charm, though its very limited power rendered it unsuitable for use in large rooms or concert halls. Nevertheless, on account of the scope which it afforded for individual expression, it was a favourite instrument with all the best musicians in its day. Bach is said to have preferred it to the harpsichord, Mozart loved to play on it, while even Beethoven, though himself long accustomed to the pianoforte, spoke of it as the most expressive of all keyboard instruments.