KEYBOARD or MANUAL. The two principal types of keyboard instruments to-day are the organ and the piano. Their keyboards, although similarly constructed, differ widely in scope and capabilities, that of the former being purely mechanical in its action and unlike that of the pianoforte, therefore, in the case of which the touch and force employed affect the quality of the sound produced. The first instrument provided with a keyboard was the organ. The earliest contrivance for opening the pipes was the simple slider, unprovided with a key or touch piece and working in a groove like the lid of a box, which was merely pushed in or drawn out. The earliest trace of a keyboard with balanced keys which we possess is contained in Hero's description of the hydraulic organ said to have been invented by Ctesibius of Alexandria in the 2nd century B.C., in the case of which the sliders were pushed forward by a key and drawn back again when the key was released by a flexible strip of horn. Sub sequently for many centuries all trace of this important develop ment disappears, sliders of all kinds with and without handles doing duty for keys until the 12th or 13th century, when we find the small portative organs furnished with narrow keys which appear to have been balanced. During the same period keys were applied for the first time to stringed instruments in the organ istrum (q.v.) and the hurdy-gurdy (q.v.) and a little later to the clavichordium and clavicymbalum and other precursors of the pianoforte. The exact date at which our chromatic keyboard
came into use has not been discovered, but it existed in the 15th century and may be studied in the picture of St. Cecilia playing the organ, on the Ghent altarpiece painted by the brothers Hubert and Jan van Eyck. Praetorius distinctly states that the large Halberstadt organ had the keyboard which he illustrates from the outset and reproduces the inscription asserting that the organ was built in 1361 by the priest Nicolas Fabri and was renovated in 1495 by Gregorius Kleng. The keyboard of this organ has the arrangement of the present day with raised black notes; it is not improbable that Praetorius' statement was correct, for Germany and the Netherlands led the van in organ-building during the middle ages.
In modern times many keyboards designed on novel lines and claiming to possess various advantages have been introduced. Of these one of the best known and most important is the double keyboard associated with the Duplex-Coupler pianoforte of Emanuel Moor, whereby the most remarkable results (in the facilitation of execution, enlargement of the instrument's re sources and so on) are undoubtedly secured. But, as in the anal ogous case of improved methods of notation, it is vastly easier to invent a new and improved keyboard than to secure its general acceptance and adoption.