In its conventional form, an organ is basically a set of pipes activated by compressed air, under the control of a keyboard. It is thought to have been invented in Hellenistic Alexandria around the beginning of the second century C.E., and was called hydraulos (ύδρανλός – water pipe) since the air was compressed by a water-pressure mechanism. During the first centuries C.E. this mechanism came to be replaced by bellows, but the name hydraulos or hydraulis remained. The instrument spread through the Roman and Byzantine Empires as a crude but effective accompaniment to games and ceremonies in the circus and at court. Byzantine influence brought the organ both to the Persian court and to Europe in the eighth or ninth centuries.
It was the late Roman and Byzantine organ, with its multiplicity of pipes and – for that time – astounding tone-volume, that gave rise to the late talmudic identification of the magrefah ("rake") as an organ supposed to have been used in the Second Temple. The development of the legend, for such it is, can easily be traced. The Mishnah (Tam. 2:1; 3:8, and 5:6) states that a magrefah was among the implements used for cleaning the altar in the morning before the new daily sacrifice; and that the noise of its being thrown on the floor was one of several "noise-cues" which the priests used to ensure the smooth running of the ceremony (cf. The Letter of Aristeas 92; 94–96) in the absence of perceptible orders during the service. A hyperbole states that all these noises were audible "unto Jericho" (Tam. 3:8). The equating of magrefah with hydraulis must have occurred in the time of the *Tosefta, since Tosefta Arakhin 1:13–14 quotes R. Simeon b. Gamaliel as saying: "There was no hydraulis [הדראוליס] in the Temple since it confuses the voice and spoils the tune." The Jerusalem Talmud (Suk. 5:6, 55c–d) quotes R. Simeon b. Gamaliel, and then goes on to identify the biblical ugav with ardablis, and states that the magrefah had ten holes (or pipes) each emitting a hundred
ANTIQUITY: Idelsohn, Music, 14, 19, 242–4, 496; J. Yasser, in: Journal of the American Musicological Society, 13 (1960), 24–42; J. Perrot, L'orgue, de ses origines helléntistiques à la fin du XIIIe siècle (1965), 14–19; H. Avenary, in: Taẓlil, 2 (1961), 66; C. Sachs, The History of Musical Instruments (1940), 124. MODERN TIMES: Sendrey, Music, nos. 2537–86; Adler, Prat Mus, 28–30, 65, 74, 112, 263; A. Berliner, Zur Lehr' und zur Wehr, ueber und gegen die kirchliche Orgel im juedischen Gottesdienste (1904); S. Krauss, Zur Orgelfrage (1919), incl. bibl.