CLAVICHORD, or Clarichord (Fr. manicorde; Ger. Clavichord; Ital. manicordo; Span. manicordio  ), a medieval 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, consisted of a rectangular case, with or without legs, often very elaborately ornamented with paintings and gilding. The earliest instruments were small and portable, being placed upon a table or stand. The strings, of finely drawn brass, steel or iron wire, were stretched almost parallel with the keyboard over the narrow belly or soundboard resting on the soundboard bridges, often three in number, and wound as in the piano round wrest or tuning pins set in a block at the right-hand side of the soundboard and attached at the other end to hitch pins. The bridges served to direct the course of the strings and to conduct the sound waves to the soundboard. The scaling, or division of the strings determining their vibrating length, was effected by the position of the tangents. These tangents, small wedge-shaped blades of brass, beaten out at the top, were inserted in the end of the arm of the keys. As the latter were depressed by the fingers the tangents rose to strike the strings and stop them at the proper length from the belly-bridge. Thus the string was set in vibration between the point of impact and the belly-bridge just as long as the key was pressed down. The key being released, the vibrations were instantly stopped by a list of cloth acting as damper and interwoven among the strings behind the line of the tangents.
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 correct position under the string. The "fret-free" were chromatically-scaled instruments. The first bund-frei clavichord is attributed to Daniel Faber of Crailsheim in Saxony about 1720. This important change in construction increased the size of the instrument, each pair of unison strings requiring a key and tangent of its own, and led to the introduction of the system of tuning by equal temperament upheld by J.S. Bach. Clavichords were made with pedals. 
The tone of the clavichord, extremely sweet and delicate, was characterized by a tremulous hesitancy, which formed its great charm while rendering it suitable only for the private music room or study. Between 1883 and 1893 renewed attention was drawn to the instrument by A.J. Hipkins's lectures and recitals on keyboard instruments in London, Oxford and Cambridge; and Arnold Dolmetsch reintroduced the art of making clavichords in 1894.
 The words clavicorde, clavicordo and clavicordio, respectively French, Italian and Spanish, were applied to a different type of instrument, the spinet (q.v.).
 See Sebastian Virdung, Musica getutscht und auszgezogen (Basel, 1511) (facsimile reprint Berlin, 1882, edited by R. Eitner); J. Verschuere Reynvaan, Musijkaal Kunst-Woordenboek (Amsterdam, 1795) (a very scarce book, of which the British Museum does not possess a copy); Jacob Adlung, Musica Mechanica Organoedi (Berlin, 1768), vol. ii. pp. 158-9; A.J. Hipkins, The History of the Pianoforte (London, 1896), pp. 61 and 62.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)