The clavichord retained the box shape of its prototype, the monochord. Originally it was portable and was set upon a table; later, however, was made, so to speak, to stand upon its own legs. In appearance it resembled our square pianofortes. It gave forth a sweet, gentle and decidedly pretty musical sound. It had a further admirable quality in its capacity for sustaining a tone, since by keeping the tangent pressed against the string the player was able to sustain the tone so long as the string continued to vibrate. Moreover, by holding down the key and at the same time making a gentle rocking motion with the finger he was able to produce a tremolo effect which German musicians called _Bebung_ (trembling), and the French _balancement_.
A defect of the clavichord was, however, its lack of power. This defect led to experiments which resulted in the construction of a keyboard instrument the strings of which, in response to the action of the keys, were set in vibration by jacks tipped with crow-quills or hard leather. The sound was much stronger than that of the clavichord. But the jacks twanged the strings with uniform power, "permitting a sharp outline, but no shading of the tones."
If you chance to be listening to a Hungarian band at a restaurant you may notice that one of the players has lying on a table before him an instrument with many strings strung very much like those of the pianoforte. It is played with two little mallets in the player's hands, and produces the weird arpeggios and improvised runs characteristic of Hungarian gypsy music. It is a very old instrument called the cembalo. About the fifteenth century, it seems, some one devised a keyboard attachment with quills for this instrument, tipped the jacks with crow-quills, and called the result a clavicembalo (a cembalo with keys). This was the origin of the harpsichord, the name by which the clavicembalo soon became more generally known. Harpsichords were shaped somewhat like our grand pianofortes, but were much smaller. A spinet was a small harpsichord, and the virginal a still smaller one. Sometimes, indeed, virginals were made no larger than workboxes, the instrument being taken out of the box and placed on a table before the player.