Clavicytherium

[T]he harpſichord is an improvement of the Clavicitherium, an inſtrument known in England in Gower's time by the name of the Citole, from Cistella, a little cheſt.

When we consider the state of imperfection in which all keyed instruments, the organ excepted, remained till within these few years past, we can scarcely bring ourselves to believe tha instruments analogous to them were in use as far back as 1530. Yet such was the case: four instruments of this kind were then employed, the compass of which was three octaves and a half. They were—1st, the Clavicitherium, which was mounted with catgut-strings, and sounded by means of a jack put in motion by the touch: […]

The first stringed instrument to which the key-board was applied, was probably the clavicytherium, or keyed-cithara. In its early stage, it was a small oblong box, with the strings arranged in the form of a half-triangle. The strings, which were of catgut, were sounded by means of quill-plectra, attached in a rude way to the ends of the keys.

[W]e find indications of a keyed instrument after the year 1300, called the Clavicytherium, or keyed cithara. The invention of keys permitted the strings to be covered over, and therefore the strings of the clavicytherium were enclosed in a box, instead of being stretched on a box. […] The clavicytherium was usually a very small instrument,—an oblong box, three or four feet in length, that could be lifted by a girl of fourteen. The clavichord and manichord, which we read of in [Wolfgang Amadeus] Mozart's letters, were only improved and better-made clavicytheria.

The writer referred to [Edward Francis Rimbault] traces the instrument from the ancient lyre, through various mechanical phases, the harp, psaltery, dulcimer, etc. to the clavicitherium—a name compounded from the Latin clavis, a key, and cithera, the name of an ancient instrument of music, which consisted of strings drawn over a sounding wooden surface or bottom, and not unlike the modern guitar. The clavicytherium was an oblong box, containing a number of strings arranged in a triangular form, and which were struck by a plectrum—a little mallet, commonly made of ivory, with which the ancients beat the strings of the lyre.

Clavicytheria, or upright harpsichords, were also made in Italy. Although they probably were built almost everywhere, the evidence of the extant instruments indicates that they were more common here than elsewhere. Playing a clavicytherium is a sensual experience: the soundboard is directly in front and the sound is projected right at the player.

However, [Albert] Delin's originality is manifested from the start through his building of clavicytheriums, in which the mechanism is an innovation; it appears that he was trying to distinguish himself from the other makers of the eighteenth century in the Low Countries.