AULOS , in Greek antiquities, a class of wood-wind instruments with single or with double reed mouthpiece and either cylindrical or conical bore, thus corresponding to both oboe and clarinet. In its widest acceptation the aulos was a generic term for instruments consisting of a tube in which the air column was set in vibration either directly by the lips of the performer, or through the medium of a mouthpiece containing a single or a double reed. Even the pipes of the pan-pipes (syrinx polycalamus,  ) were sometimes called auloi . The aulos is also the earliest prototype of the organ, which, by gradual assimilation of the principles of syrinx and bag-pipe, reached the stage at which it became known as the Tyrrhenian aulos (Pollux iv. 70) or the hydraulos, according to the method of compressing the wind supply (see Organ: Early History; and Syrinx). The aulos in its earliest form, the reed pipe, during the best classical period had a cylindrical bore like that of the modern clarinet, and therefore had the acoustic properties of the stopped pipe, whether the air column was set in vibration by means of a single or of a double reed, for the mouthpiece does not affect the harmonic series.  To the acoustic properties of open or stopped pipes are due those essential differences which underlie the classification of modern wind instruments. A stopped pipe produces its fundamental tone one octave lower than the tone of an open pipe of corresponding length, and overblows the harmonics of the twelfth, and of the third above the second octave of the fundamental tone, i.e. the odd numbers of the series; whereas the open pipe gives the whole series of harmonics, the octave, the twelfth, the double octave, and the third above it, etc.
To produce the diatonic scale throughout the octaves of its compass, the stopped pipe requires eleven lateral holes in the side of the pipe, at appropriate distances from each other, and from the end of the pipe, whereas the open pipe requires but six. The acoustic properties of the open pipe can only be secured in combination with a reed mouthpiece by making the bore conical. The late Romans (and therefore we may perhaps assume the Greeks also, since the Romans acknowledge their indebtedness to the Greeks in matters relating to musical instruments, and more especially to the cithara and aulos) understood the acoustic principle utilized to-day in making wind instruments, that a hole of small diameter nearer the mouthpiece may be substituted for one of greater diameter in the theoretically correct position. This is demonstrated by the 4th-century grammarian Macrobius, who says (Comm. in Somn. Scip. ii. 4, 5): "Nec secus probamus in tibiis, de quarum foraminibus vicinis inflantis ori sonus acutus emittitur, de longinquis autem et termino proximis gravior; item acutior per patentiora foramina, gravior per angusta" (see Bassoon). Aristotle gives directions for boring holes in the aulos, which would apply only to a pipe of cylindrical bore (Probl. xix. 23). At first the aulos had but three or four holes; to Diodorus of Thebes is due the credit of having increased this number (Pollux iv. 80). Pronomus, the musician, and teacher of Alcibiades (5th century B.C.), further improved the aulos by making it possible to play on one pair of instruments the three musical scales in use at his time, the Dorian, the Phrygian, and the Lydian, whereas previously a separate pair of pipes had been used for each scale (Pausanias ix. 12. 5; Athenaeus xiv. 31). These three modes would require a compass of a tenth in order to produce the fundamental octave in each.
There are two ways in which this increased compass might have been obtained: (1) by increasing the number of holes and covering up those not required, (2) by means of contrivances for lowering the pitch of individual notes as required. We have evidence that both means were known to the Greeks and Romans. The simplest device for closing holes not in use was a band of metal left free to slide round the pipe, and having a hole bored through it corresponding in diameter with the hole in the pipe. Each hole was provided with a band, which was in some cases prevented from slipping down the pipe by narrow fixed rings of metal. The line on fig. 1 between r and s is thought to have been one of these rings.
Some pipes had two holes pierced through the bands and the bone, in such a manner that only one could be exposed at a time. This is clearly shown in the diagram (fig. 1) of fragments of an aulos from the museum at Candia, for which the writer is greatly indebted to Professor John L. Myres, by whom measured drawings were made from the instrument in 1893. These highly interesting remains, judging from the closed end (5), seem to belong to a side-blown reed-pipe similar to the Maenad pipes in the Castellani collection at the British Museum, illustrated below; they are constructed like modern flutes, but played by means of a reed inserted into the lateral embouchure.
In the Candia pipe, it seems likely that Nos. 1 and 2 represented the bell end, slightly expanded, No. 3 joining the broken end of No. 2 at l; there being a possible fit at the other end at s with a in No. 4 (the drawings must in this case be imagined as reversed for parts 3 and 4), and No. 5 joining on to No. 4 at k.
According to Professor Myres there are fragments of a pair of pipes in the Cyprus Museum of precisely the same construction as the one in Candia. In the drawing, the shape and relative position of the holes on the circumference is approximate only, but their position lengthways is measured.
Bands of silver were found on the ivory pipes from Pompeii  (fig. 2), as well as on two pipes belonging to the Castellani collection (fig. 4) and on one from Halicarnassus, in the British Museum. In order to enable the performer to use these bands conveniently, a contrivance such as a little ring, a horn or a hook termed keras was attached to the band. 
Thirteen of the bands on the Pompeian pipes still have sockets which probably originally contained kerata. Pollux (iv. 80) mentions that Diodorus of Thebes, in order to increase the range of the aulos, made lateral channels for the air . These consisted of tubes inserted into the holes in the bands for the purpose of lengthening the column of air, and lowering individual notes at will, the sound being then produced at the extremity of the tube, instead of at the surface of the pipe. It is possible that some of the double holes in the slides of the Candia pipe were intended for the reception of these tubes. These lateral tubes form the archetype of the modern crook or piston.  The mouthpiece of the aulos was called zeugos ,  the reed tongue glossa  or glotta ( or ), and the socket into which the reed was fixed glottis  .
The double reed was probably used at first, being the simplest form of mouthpiece; the word zeugos, moreover, signifies a pair of like things. There is, however, no difficulty in accepting the probability that a single beating reed or clarinet mouthpiece was used by the Greeks, since the ancient Egyptians used it with the as-it or arghoul (q.v.).
(Drawn from a photo by Brogi.)
Fig. 2. - Roman Ivory Aulos found at Pompeii (Naples Mus.), showing slides and rings.
The beak-shaped mouthpiece of a pipe found at Pompeii (fig. 3) has all the appearance of the beak of the clarinet, having, on the side not shown, the lay on which to fix a single or beating reed.  It may, however, have been the cap of a covered reed, or even a whistle mouthpiece in which the lip does not show in the photograph. It is difficult to form a conclusion without seeing the real instrument. On a mosaic of Monnus in Trèves  is represented an aulos which also appears to have a beak-shaped mouthpiece.
The upper part of the aulos, as in the Pompeian pipes, frequently had the form of a flaring cup supported on a pear-shaped bulb, respectively identified as the holmos and the hypholmion , the support of the holmos. An explanation of the original nature and construction of the bulb and flaring cup, so familiar in the various representations of the aulos, and in the real instruments found in Pompeii, is provided by an ancient Egyptian flute belonging to the collection of G. Maspero, illustrated and described by Victor Loret.  Loret calls the double bulb the beak mouthpiece of the instrument, and describes its construction; it consists of a piece of reed of larger diameter than that of the flute, and eight centimetres long; this reed has been forcibly compressed a little more than half way down by means of a ligature of twine, thus reducing the diameter from 6 mm. to 4 mm. The end of the pipe, covered by rows of waxed thread, fits into the end of the smaller bulb, to which it was also bound by waxed thread exactly as in the Elgin pipe at the British Museum, described below. There is no indication of the manner in which the pipe was sounded, and Loret assumes that there was once a whistle or flageolet mouthpiece. To the present writer, however, it seems probable that the constricted diameter between the two bulbs formed a socket into which the double reed or straw was inserted, and that, in this case at least, the reed was not taken into the mouth, but vibrated in the upper bulb or air-chamber. This simple contrivance was probably also employed in the earliest Greek pipes, and was later copied and elaborated in wood, bone or metal, the upper bulb being made shorter and developing into the flaring cup, in order that the reeds might be taken directly into the mouth. During the best period of Greek music the reeds were taken directly into the mouth  and not enclosed in an air-chamber. The two pipes were kept in position while the fingers stopped the holes and turned the bands by means of the (Lat. capistrum), a bandage encircling mouth and cheeks, and having holes through which the reed-mouthpiece passed into the mouth of the performer; the phorbeia also relieved the pressure of the breath on the cheeks and lips,  which is felt more especially by performers on oboe and bassoon at the present day.
(From a photo by Brogi.)
Fig. 3. - Beak mouthpiece. Found at Pompeii (Naples Mus.).
In the pair of wooden pipes belonging to the Elgin collection at the British Museum, one of the bulbs, partly broken, but preserved in the same case as the pipes, was fastened to the pipes by means of waxed thread, the indented lines being still visible on the rim of the bulb. The aulos was kept in a case called sybene  or aulotheke  , and the little bag or case in which the delicate reeds were carried was known by the name of glottokomeion  .  Two Egyptian flute cases are extant, one in the Louvre,  and the other in the museum at Leiden. The latter case is of sycamore wood, cylindrical in shape, with a stopper of the same wood; there is no legend or design upon it. The case contained seven pipes, five pieces of reed without bore or holes, and three pieces of straw suitable for making double-reed mouthpieces. 
Aristoxenus gives the full compass of a single pipe or pair of pipes as over three octaves: - "For doubtless we should find an interval greater than the above mentioned three octaves between the highest note of the soprano clarinet (aulos) and the lowest note of the bass-clarinet (aulos); and again between the highest note of a clarinet player performing with the speaker open, and the lowest note of a clarinet player performing with the speaker closed." 
This, according to the tables of Alypius, would correspond to the full range of the Greek scales, a little over three octaves from to It is evident that the ancient Greeks obtained this full compass on the aulos by means of the harmonics. Proclus (Comm. in Alcibiad. chap. 68) states that from each hole of the pipe at least three tones could be produced. Moreover, classic writers maintain that if the performer press the zeugos or the glottai of the pipes, a sharper tone is produced.  This is exactly how a performer on a modern clarinet or oboe produces the higher harmonics of the instrument.  The small bore of the aulos in comparison to its length facilitated the production of the harmonics (cf. Zamminer p. 218), as does also the use of a small hole near the mouthpiece, called in Greek syrinx and in the modern clarinet the "speaker," which when open enables the performer to overblow with ease the first harmonic of the lowest fundamental tones. To Mr Albert A. Howard of Harvard University is due the credit of having identified the syrinx of the aulos with the speaker of the clarinet.  This assumption is doubtless correct, and is supported by classical grammarians,  who state that the syrinx was one of the holes of the aulos. It renders quite clear certain passages in Aristoxenus, Aristotle and Plutarch, and a scholion to Pindar's 12th Pythian, which before were difficult to understand (see Syrinx).
Fig. 4. - The Plagiaulos. Castellani Collection (Maenad Pipes), British Museum.
Fig. 5. - Ancient Greek Double Pipes. Elgin Collection, British Museum.
The aulos or tibia existed in a great number of varieties enumerated by Pollux (Onomast. iv. 74 et seq.) and Athenaeus (iv. 76 et seq.). They fall into two distinct classes, the single and the double pipes. There were three principal single pipes, the monaulos, the plagiaulos and the syrinx monocalamos. The double pipes were used by the great musicians of ancient Greece, and notably at the musical contests at Delphi, and what has been said above concerning the construction of the aulos refers mainly to the double pipes. The monaulos, a single pipe of Egyptian origin, which, by inference, we assume to have been played from the end by means of a reed, may have been the archetype of the oboe or clarinet. The plagiaulos photinx or tibia obliqua, invented by the Libyans (Pollux iv. 74), or, according to Pliny (vii. 204), by Midas of Phrygia, was held like the modern flute, but was played by means of a mouthpiece containing a reed. Three of the existing pipes at the British Museum (the two in the Castellani collection, and the pipe from Halicarnassus) belong to this type. The mouthpiece projects from the side of the pipe and communicates with the main bore by means of a slanting passage; the end nearest the mouthpiece is stopped as in the modern flute; in the latter, however, the embouchure is not closed by the lips when playing, and therefore the flute has the acoustic properties of the open pipe, whereas the plagiaulos having a reed mouthpiece gave the harmonics of a closed pipe. The double pipes existed in five sizes according to pitch, in the days of Aristoxenus, who, in a treatise on the construction of the auloi , unfortunately not extant,  divides them thus: -
(1) Parthenioi auloi , the maiden's auloi, corresponding to the soprano compass.
(2) Paidikoi auloi , the boy's pipes or alto auloi, used to accompany boys' songs and also in double pairs at feasts.
(3) Kitharisterioi auloi , used to accompany the cithara.
(4) Teleioi auloi, the perfect aulos, or tenor's pipes; also known as the pythic auloi ; used for the paeans and for solos at the Pythean games (without chorus). It was the pythic auloi and the kitharisterioi auloi more especially which were provided with the speaker (syrinx) in order to improve the harmonic notes (see Syrinx).
(5) Hyperteleioi auloi or andreioi auloi (see Athenaeus iv. 79), the bass-auloi.
The Phrygian pipes or auloi Elymoi  were made of box-wood and were tipped with horn; they were double pipes, but differed from all others in that the two pipes were unequal in length and in the diameter of their bores;  sometimes one of the pipes was curved upwards and terminated in a horn bell;  they seem to have had a conical bore, if representations on monuments are to be trusted. We may conclude that the archetype of the oboe with conical bore was not unknown to the Greeks; it was frequently used by the Etruscans and Romans, and appears on many has-reliefs, mural paintings and other monuments. For illustrations see Wilhelm Froehner, Les Musées de France, pl. iii., "Marsyas playing the double pipes." There the bore is decidedly conical in the ratio of at least 1 : 4 between the mouthpiece and the end of the instrument; the vase is Roman, from the south of France. See also Bulletino della Commissione Archeologica Comunale di Roma, Rome, 1879, vol. vii., 2nd series, pl. vii. and p. 119 et seq., "Le Nozze di Elena e Paride," from a bas-relief in the monastery of S. Antonio on the Esquiline; Wilhelm Zahn, Die schonsten Ornamente und die merkwurdigsten Gemälde aus Pompeji, Herkulaneum und Stabiae (German and French), vol. iii., pl. 43 and 51 (Berlin, 1828-1859).
For further information on the aulos, consult Albert A. Howard, "The Aulos or Tibia," Harvard Studies, iv., 1893; François A. Gevaert, Histoire de la musique dans l'antiquité, vol. ii. p. 273 et seq.; Carl von Jan's article "Flote" in August Baumeister's Denkmaler des klassischen Altertums (Munich, 1884-1888), vol. i.; Dr Hugo Riemann, Handbuch der Musikgeschichte, Bd. I.T. 1, pp. 93-112 (Leipzig, 1904); Caspar Bartholinus, De Tibiis Veterum (Amsterdam, 1779).
 See Pollux, Onom. iv. 69.
 See Friedrich Zamminer, Die Musik und musikalischen Instrumente in ihrer Beziehung zu den Gesetzen der Akustik (Giessen, 1855), p. 305.
 These pipes were discovered during the excavations in 1867, and are now in the museum at Naples. Excellent reproductions and descriptions of them are given in "The Aulos or Tibia," by Albert A. Howard, Harvard Studies, vol. iv. (Boston, 1893), pl. ii. and pp. 48-55.
 For illustrations of auloi provided with these contrivances, see illustration (fig. 2) of an aulos from Pompeii; a relief in Vatican, No. 535; Helbig's Wandgemãlde, Nos. 56, 69, 730, 765, etc.
 For illustrations of showing the holes at the ends of the tubes, see Description des marbres antiques du Musée Campana, by H. d'Escamps, pl. 25; Wilhelm Froehner's Catalogue of the Louvre, No. 378; Glyptothek Museum at Munich, No. 188; Albert A. Howard, "The Aulos or Tibia," Harvard Studies, iv. (Boston, 1893), pl. 1, No. 1.
 For a description of the reed calamus from which pipe and mouthpiece were made see Theophrastus, Hist. Plant. iv. 11.
 Aeschines 86. 29; Aristotle, H.A. 6, 10, 9, etc.
 Lucian, Harm. 1.
 Cf. article Mouthpiece.
 See Antike Denkmaler, Deutsches archäol. Inst., Berlin, 1891, vol. i. pi. 49.
 See "Les Flûtes égyptiennes antiques," Journal asiatique, 8th ser. vol. xiv. (Paris, 1889), pp. 212-215.
 See Aristotle, De Audib. p. 802 b, 18, and p. 804a; Festus, ed. Mueller, p. 116.
 See Albert A. Howard, op. cit. p. 29, and Dr Hugo Riemann, Gesch. d. Musik, Bd. i. T. 1, p. 111 (Leipzig, 1904).
 Pollux, Onomasticon, vii. 153.
 Pollux ii. 108, vii. 153, x. 153-154; A.A. Howard, op. cit. pp. 26-27. An illustration of the little bag is given in Denkmaler des klassischen Altertums, by August Baumeister, vol. i. p. 554, fig. 591.
 Two Egyptian pipes now in the Louvre were found in a case ornamented with a painting of a female musician playing a double pipe. See E. de Rougé, Notice sommaire des monuments égyptiens exposés dans les galeries du Louvre, p. 87.
 See Victor Loret, "Les Flûtes égyptiennes antiques," in Journal asiatique, vol. xiv. (Paris, 1889), pp. 199, 200 and 201 (note), pp. 207, 211 and 217, and Conrad Leemans, Description raisonnée des monuments égyptiens du Musée d'Antiquités de Leyde, p. 132, No. 489; contents of case Nos. 474-488.
 Aristoxenus, Harm. bk. i. 20 and 21, H.S. Macran's edition with translation (Oxford, 1902), p. 179.
 Aristotle, De audib. p. 804a; Porphyry, ed. Wallis, p. 249; ibid. p. 252.
 Zamminer, op. cit. p. 301.
 Op. cit. p. 32-35.
 See Etymologicum magnum (Augsburg. 1848), s.v. "Syrinx."
 See Athenaeus xiv. 634, who quotes from Didymus.
 Pollux iv. 74.
 Servius ad Aen. ix. 615.
 Tibullus ii. 85; Virg. Aen. xi. 735; Ovid, Met. iii. 533, Ex Ponto i. 1. 39.
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)