The sound is produced by holding the flute transversely with the embouchure turned slightly outwards, the lower lip resting on the nearer edge of the embouchure, and blowing obliquely across, not into, the orifice. The flat stream of air from the lips, known as the air-reed, breaks against the sharp outer edge of the embouchure. The current of air, thus set in a flutter, produces in the stationary column of air within the tube a series of pulsations or vibrations caused by the alternate compression and rarefaction of the air and generating sounds of a pitch proportional to the length of the stationary column, which is practically somewhat longer than the length of the tube.[1] The length of this column is varied by opening the lateral finger-holes. The current or air-reed thus acts upon the air column within the flute, without passing through the tube, as a plectrum upon a string, setting it in vibration. The air column of the flute is the sound-producer, whereas in instruments with reed mouthpieces the vibrating reed is more properly the sound-producer, while the air column, acting as a resonating medium, reinforces the note of the reed by vibrating synchronously with it. If the angle[2] at which the current of air is directed against the outer edge of the embouchure be made less acute and the pressure of the breath be at the same time increased, the frequency of the alternate pulses of compression and rarefaction within the tube will be increased two, three or fourfold, forming a corresponding number of nodes and loops which results in harmonics or upper partials, respectively the octave, the twelfth, the double octave. By this means sounds of higher pitch are produced without actually shortening the length of the column of air by means of lateral holes. The acoustic theory of sound-production in the flute is one on which there is great diversity of opinion. The subject is too vast to be treated here, but readers who wish to pursue it may consult the works of Rockstro,[3] Helmholtz,[4] and others.[5] The effect of boring lateral holes in pipes is to shorten the vibrating length of the air column, which may be regarded as being effective only between the hole in question and the mouthpiece. In order to obtain this result the diameter of the hole should be equal to that of the bore; as long as the holes were covered by the fingers, this was obviously impossible. The holes, therefore, being smaller than the laws of acoustics demand, have to be placed proportionally nearer the mouthpiece in order to avoid deepening the pitch and deadening the tone. This principle was understood by wind-instrument makers of classic Greece (see [Aulos] and [Clarinet]), and has been explained by Chladni[6] and Gottfried Weber.[7]
| From Captain Day’s Catalogue, &c., by permission of Messrs. Eyre & Spottiswoode. |
| Fig. 1.—Eight-keyed Cone Flute by Richard Potter. 18th century. |
| Messrs. Rudall, Carte & Co. |
| Fig. 2.—Boehm Cylinder Flute. Rockstro Model. |
The bore of the early flute with six finger-holes was invariably cylindrical throughout, but towards the end of the 17th century a modification took place, the head joint alone remaining cylindrical while the rest of the bore assumed the form of a cone having its smallest diameter at the open end of the tube. The conoidal bore greatly improved the quality of tone and the production of the higher harmonics of the third octave. Once the conical bore had been adopted, the term flute was exclusively applied to the new instruments, the smaller flutes, then cylindrical, used in the army being designated fife (q.v.). At the present day in England, France and America, the favourite mode of construction is that introduced by Theobald Boehm, and known as the “cylinder flute with the parabolic head,” of which more will be said further on. The successive opening of the holes and keys on the flute produces the chromatic scale of the first or fundamental octave. By increasing the pressure of the breath and slightly altering the position of the lips over the mouth-hole, the same fingering produces the notes of the fundamental octave in the next octave higher. The third octave of the compass is obtained by the production of the higher harmonics (Fr. sons harmoniques; Ger. Flageolettöne), of the fundamental scale, facilitated by the opening of certain of the finger-holes as “vent holes.” The quality of tone depends somewhat on the material of which the flute is made; silver and gold produce a liquid tone of exquisite delicacy suitable for solo music, cocus-wood and ebonite a rich mellow tone of considerable power suitable for orchestral music. The tone differs further in the three registers, the lowest being slightly rough, the medium sweet and elegiac, and the third bird-like and brilliant. The proportions, position and form of the stopper and of the air chamber situated between it and the embouchure are mainly influential in giving the flute its peculiar slightly hollow timbre, due to the paucity of the upper partials of which according to Helmholtz[8] only the octave and twelfth are heard. Mr Blaikley[9] states, however, that when the fundamental D is played, he can discern the seventh partial. The technical capabilities of the flute are practically unlimited to a good player who can obtain sustained notes diminuendo and crescendo, diatonic and chromatic scales and arpeggios both legato and staccato, leaps, turns, shakes, &c. By the articulation with the tongue of the syllables te-ke or ti-ke repeated quickly for groups of double notes, or of te-ke-ti for triplets, an easy effective staccato is produced, known respectively as double or triple tonguing, a device understood early in the 16th century and mentioned by Martin Agricola,[10] who gives the syllables as de for sustained notes, di-ri for shorter notes, and tel-lel-lel for staccato passages in quick tempo.[11]
Musical instruments, such as flutes, in which a column of air is set in vibration by regular pulsations derived from a current of air directed by the lips of the executant against the side of the orifice serving as embouchure, appear to be of very ancient origin. The Hindus, Chinese and Japanese claim to have used these modes of blowing from time immemorial. The ancient Egyptians had a long pipe held obliquely and blown across the end of the pipe itself at its upper extremity; it was known as Saïb-it[12] and was frequently figured on the monuments. The same instrument, called “nay,” is still used in Mahommedan countries. The oblique aulos of the Greeks, plagiaulos,[13] was of Egyptian origin and was perhaps at first blown from the end as described above,[14] since we know that the Greeks were familiar with that method of blowing in the syrinx or pan-pipe. The instruments preserved at the British Museum[15] having lateral embouchures show, however, that they were also acquainted—probably through the Hindus—with the transverse flute, although in the case of these specimens a reed must have been inserted into the mouth-hole or no sound would have been obtained.
| Fig. 3.—Transverse Flute. 1st or 2nd century A.D. From the Tope at Amarābati, British Museum. |
The high antiquity of a lateral embouchure in Europe is generally admitted; the flute evidently penetrated from the East at some period not yet determined. A transverse flute is seen on Indian sculptures of the Gandhara school showing Greek influence, and dating from the beginning of our era (fig. 3). But although the transverse flute was evidently known to the Greeks and Romans, it did not find the same favour as the reed instruments known as auloi. We have no evidence of the survival of the transverse flute after the fall of the Roman empire until it filtered through from Byzantine sources during the early middle ages. Instances of the flute occur on a group of caskets[16] of Italo-Byzantine work of the 9th or 10th century, while of purely Byzantine origin we find examples of flutes in Greek MSS.[17] preserved in Paris, at the British Museum and elsewhere. There is moreover in the cathedral of St Sophia at Kiev[18] an orchestra depicted on frescoes said to date from the 11th century; among the musicians is a flautist.
The first essentially western European trace of the transverse flute occurs in a German MS. of the 12th century, the celebrated Hortus deliciarum of the abbess Herrad von Landsperg.[19] Fol. 221 shows a syren playing upon the transverse flute, which Herrad explains in a legend as tibia; in the vocabulary the latter is translated swegel. In the 13th century it occurs among the miniatures of the fifty-one musicians in the beautiful MS. Las Cantigas de Santa Maria in the Escorial, Madrid.[20] Eustache Deschamps, a French poet of the 14th century, in one of his ballads, makes mention of the “flute traversaine,” and we are justified in supposing that he refers to the transverse flute. It had certainly acquired some vogue in the 15th century, being figured in an engraving in Sebastian Virdung’s celebrated work,[21] where it is called “Zwerchpfeiff,” and, with the drums, it already constituted the principal element of the military music. Agricola (op. cit.) alludes to it as the “Querchpfeiff” or “Schweizerpfeiff,” the latter designation dating, it is said, from the battle of Marignan (1515), when the Swiss troops used it for the first time in war.
From Agricola onwards transverse flutes formed a complete family, said to comprise the discant, the alto and tenor, and the bass—