THE organ (German, Orgel; French, orgue; Italian, organo) has been called the king of instruments; but if the title is correct, it has had a much longer reign than usually falls to the lot of royalty.
"The just designs of Greece," which the poet Collins seemed to think superior to "Cecilia's mingled world of sound," had no place for the organ, unless we accept as a primitive organ the syrinx, or set of Pan-pipes. That the organ sometimes took such a small form is shown by the regals of Monteverde's seventeenth-century orchestra, which was a tiny portable organ somewhat resembling the syrinx. The larger stationary organ of Monteverde's day was known as the positive; and this term is still kept to describe the choir organ in France and Germany.
Rome had a somewhat mysterious water-organ, worked by hydraulic pressure. Its construction is not now known, in spite of references to it by Vitruvius and others.
The Eastern Empire kept the organ, though with human instead of hydraulic motor power. In the eighth century, the Byzantine Emperor sent an organ as a present to King Pepin of France. These early organs were noisy affairs, without the selective power that comes with the use of stops; and when a note was played, all the pipes of that pitch gave their tone together. It is on record that a lady at Charlemagne's court was driven crazy by hearing the organ unexpectedly for the first time. A century or more later, the organ at Winchester, England, was described by the monk. Wulstan as having "a noise like thunder."
The idea of stops grew up gradually in the middle ages. Stops depend on the simple principle of having two operations necessary, instead of one, to let the air into an organ pipe. Pressing down a key must be preceded by a drawing out, or other adjustment, of the stop. Each stop operates a bar, known as a slider, which keeps its set of pipes closed until certain holes in the slider are brought directly under the corresponding pipe openings. After one or more