rejected, and ‘_clavi_’ substituted (Lat. _clavis_, a key). The _clavis_ is the key which in the organ admits the wind to the pipes, in the clavier sets the strings in motion. [Illustration: From the Weimar “Wunderbuch,” a Clavichord of about 1440. One of the oldest representations.] [Illustration: From the Weimar “Wunderbuch,” Primitive Spinet, of about 1440. One of the oldest representations.] The clavichord introduced a new means of “expression,” viz., the “Bebung” (trembling, shivering), which could be applied to any of the notes by a gentle after-pressure of the key, a mournful, soul-moving _vibrato_, which was only possible with the peculiar mechanism of the clavichord, where a “tangent” both divided the string and at the same moment instantaneously created the sound. A slight relaxation of this pressure on the key caused a slight lowering of pitch; a slight renewal of pressure a corresponding heightening. The German players of the eighteenth century could scarcely find it in their hearts to resign this delicate effect, even for the advantages of the modern pianoforte. Here for the first time the keyboard mechanism had succeeded in producing a modification of the tones by “touch” alone, and the keyed instrument had gained its soul. How confined were the old eight keys of the Hurdygurdy,[20] the favourite instrument till the rise of the lute, where the strings were strained against a rosined wheel turned by a crank (a sort of everlasting fiddle-bow), while the keys divided the strings into notes--an antiquated compromise between clavier and violin! How clumsy was the treatment of the organ-keys so late as the fourteenth century, in which, according to Prätorius, the keys were struck with the fist! But from this time the art of mechanics develops quickly, and the rapid increase of the number of keys in the clavichord shows us how speedily its supremacy was attained. The fall of the key was shallow, the quick-sounding tone encouraged ornamental flourishes, which were more easily played on the clavichord than on our heavy-touched pianoforte. Yet it was long before the number of strings became equal to that of the keys. Not till the eighteenth century (about 1725) do we find clavichords with a string to every key. (These are called _free_ instruments, in contra-distinction to the old _tied_.)[21] It is obvious that the “tied” clavichords did not admit of _all_ chords; but those which were impossible were discords, avoided on other grounds by the older music. To sound C and D flat together was impossible; but no one complained, for no one, for reasons of style, wished to try it. But, on very old clavichords, C and E are also incapable of being simultaneously sounded--a fact which gives us many a hint for the criticism of the oldest pieces.