PIANOFORTE. The group of keyed stringed musical instru ments, among which the pianoforte is latest in order of time, has been invented and step by step developed with the modern art of music. During the loth century the "organum" arose, an elemen tary system of accompaniment to the voice, consisting of fourths and octaves below the melody and moving with it, and the organ (q.v.), the earliest keyed instrument, was, in the first instance, the rude embodiment of this idea and convenient means for its expression. About the same time arose a large stringed instru ment, the organistrum, the parent of the now obsolete hurdy gurdy; as the organ needed a blower as well as an organist, so the player of the organistrum required a handle-turner, by whose aid the three strings of the instrument were made to sound simultaneously upon a wheel, and, according to the well known sculptured relief of St.
George de Boscherville, one of the strings was manipulated by means of a row of stoppers or tangents pressed inwards to produce the notes. The other strings were drones, analo gous to the drones of the bag pipes, but originally the three strings followed the changing organum.
In the iith century (the epoch of Guido of Arezzo [q.v.], to whom the beginning of musi cal notation is attributed), the Pythagorean monochord, with its shifting bridge, was used in the singing schools to teach the in tervals of the plain-song of the church. The practical necessity, not merely of demonstrating the proportionate relations of the in tervals, but also of initiating pupils into the different gradations of the church tones, had soon after Guido's time brought into use quadruplex monochords, which were constructed with scales so that four lines indicated authentic and the four plagal tones. This arrangement found great acceptance, for Aribo, writing about fifty years after Guido, says that few monochords were to be found without it. Aribo strenu ously endeavoured to improve it, and "by the grace of God" in vented a monochord measure which, on account of the rapidity of the leaps he could make with it, he named a caprea (wild goat). Jean de Muris (Musica speculativa, 1323) describes the musical instruments known in his time, but does not mention the clavi chord or monochord with keys, which could not have been then invented. Perhaps one of the earliest forms of such an instrument,
in which stoppers or tangents had been adopted from the organi strum, is shown in fig. 1, from a wood carving of a vicar choral or organist, preserved in St. Mary's church, Shrewsbury. The latest date to which this figure may be attributed is 1460.
In the Weimar Wunderbuch, a MS. dated 1440 with pen and ink miniatures is given a "clavichordium" having 8 short and apparently 16 long keys. The artist has drawn 1 2 strings in a rectangular case, but no tangents are visible. A keyboard of balanced keys existed in the little portable organ known as the regal, so often represented in old carvings, paintings and stained windows. Vitruvius, De architectura, lib. x. cap. xi., translated by Newton, describes a balanced keyboard; but the key apparatus is more particularly shown in The Pneumatics of Hero of Alex andria, translated by Bennet Woodcroft (London, 1851).
The name of regal was derived from the rule (regula) or gradu ated scale of keys, and its use was to give the singers in religious processions the note or pitch. The only instrument of this kind known to exist in the United Kingdom is at Blair Atholl, and it bears the very late date of 1630. The Brussels regal may be as modern. (See Victor C. Mahillon, Catalogue Descriptif [188o], I. p. 320, p. 454.) We attribute the adaptation of the narrow regal keyboard to what was still called the monochord, but was now a complex of monochords over one resonance board, to the latter half of the 14th century; it was accomplished by the sub stitution of tangents (fixed in the ends of the balanced keys) for the movable bridges of the monochord or such stoppers as are shown in the Shrewsbury carving. Thus the monochordium or "payre of monochordis" became the clavichordium or "payre of clavichordis"—pair being applied, in the old sense of a "pair of steps," to a series of degrees. Ed. van der Straeten (La Musique aux Pays Bas, i. 278) reproduces a so-called clavichord of the 15th century from a MS. in the public library at Ghent. The treatise is anonymous, but other treatises in the same MS. bear dates 1503 and 1504. In the Weimar Wunderbuch is a pen-and-ink sketch of the "clavicimbalum" placed upon a table, in which we recognize the outline of the harpsichord, but on a smaller scale.