ORGAN, in music, the name given to the well-known wind instrument (from Gr. 6p-yavoy, Lat. organum, instrument).
The earliest authentic records of the organ do not extend beyond the second century B.C., but the evolution of the instrument from the syrinx (q.v.) or Pan-pipe goes back to a remote period. The hydraulic and pneumatic organs of the ancients were prac tically the same instrument, differing only in the method adopted for the compression of the wind supply; and the syrinx seems to have been recognized by the ancients as the precursor of both. Thus Hero of Alexandria, in his description of the hydraulic organ, calls it a syrinx. Philo of Alexandria (c. 200 B.C.), mentioning the invention of the hydraulis by Ctesibius, says, "the kind of syrinx played by hand which we call hydraulis." In the earliest organs there is no doubt that the pipes consisted of lengths of the large reed known as rceaauos used for the syrinx, but converted into open flue-pipes. Instead of cutting off the reed immediately under the knot, as for syrinx pipes, a little extra length was left and shaped to a point to form a foot or mouth piece, which was placed over the aperture in the wind-chest, so that it caused the stream of air to split in two as it was driven through the hole into the pipe by the action of the bellows. A narrow fissure was made through the knot near the front of the pipe, and above it a horizontal slit was cut in the reed, the two edges being bevelled inwards. When the wind was pumped into the chest it found an outlet through one of the holes in the lid, and the current, being divided by the foot of the pipe, became compressed and was forced through the fissure in the knot. It then ascended the pipe in an even stream, as yet silent, until thrown into commotion by another obstacle, the upper sharp edge or lip of the notch, which produced the regular flutterings or pulses requisite for the emission of a note.
In order to convert the syrinx into a mechanically played instru ment, the addition of the actuating principle of the bag-pipe was necessary. It is probable that in the earliest attempts the leather bag was actually retained and that the supply of wind was still furnished by the mouth through an insufflation pipe. Such an
instrument is described and illustrated by Father Athanasius Kircher, but his drawing should be accepted with reserve. In the instrument, which he calls the Magraketha or Mashrokitha of the Chaldees, the bag is described as being inside the wind-chest, the intufflation pipe being carried through a hole in the side of the box. Little wooden sliders manipulated by the fingers formed a means of controlling the escape of the wind through any given pipe.
Of organs in the next stage of development, namely with bel lows, several examples in pottery are extant, and also a description in the Talmud. The quotation as given by Blasius Ugolinus states that the instrument known as the Magrepha d'Aruchin "consisted, as the Schilte Haggiborim teaches, of several rows of pipes and was blown by bellows. It had, besides, holes and small sliders answering to each pipe, which were set in motion by the pressure of the organist ; the vent-holes being open, a wonderful variety of sounds was produced." In regard to the hydraulic organ, some writers have considered that the invention of the hydraulis in the 2nd century B.C. by Ctesibius of Alexandria constituted the invention of the organ, and that the pneumatic organ followed as an improvement or variety, but such a suggestion can hardly be accepted. It is most improbable that a man busy with the theory and practice of hydraulics would invent a highly complex musical instrument in which essential parts lying outside his realm, such as the flue pipes, the balanced keyboard, the arrangements within the wind chest for the distribution of the wind, are all in a developed state. It would be a case for which no parallel exists in the history of musical instruments, all of which have evolved slowly and surely through the ages. On the other hand, given a pneumatic organ in which the primitive unweighted bellows worked unsatisfactorily, an engineer would be prompt to see an opportunity for the advan tageous application of his art. There are two detailed descriptions of the hydraulis extant, both of which presuppose the existence of a pneumatic organ. One is in Greek by Hero of Alexandria, the other in Latin by Vitruvius (De Arch. lib. x. cap. ii.).