Faà di Bruno, Giovanni Matteo [Horatio, Orazio] 83

I. General

1. Acoustics.

2. Classification and distribution.

Flute: 1. General

1. Acoustics.

Generically, a flute is any instrument having an air column confined in a hollow body – whether tubular or vessel – and activated by a stream of air striking against the edge of an opening, producing what acousticians call an ‘edge tone’ (see Acoustics, §IV, 7); flutes are therefore often called edge-tone instruments. The edge is generally referred to as ‘sharp’, although sharpness is by no means necessary and may even be a disadvantage, as for example, on the modern orchestral flute – most makers prefer a slightly rounded edge. The opening is either at one end of a tube, or in the side of a tube or vessel. The air stream may be shaped and directed by the player’s lips as on the modern orchestral flute; confined in a channel, or duct, which leads the air across the hole, as on the Recorder or Whistle; or produced by the wind, as in the bulu pārinda, a large (up to 10 metres in length) aeolian pipe hung in treetops in Southeast Asia.

Where the air meets the edge it is divided, peeling off in vortices like miniature swiss rolls, alternately outside and inside the instrument. The pitch produced is determined mainly by the length of the tube or the volume of the vessel, although other factors such as the shape and diameter of the air body and the area of any open holes (including the embouchure hole) are also influential. If, with a tube, the distal end is closed, the length is effectively almost doubled, and the pitch produced is almost an octave lower; ‘almost’ because the true acoustic length of the open tube is slightly longer than the tube itself, a factor called end-correction. When the end is closed, the length of the tube is doubled but not this slight elongation of the air column, and thus the lower pitch is very slightly sharper than a true octave. If the uppermost range of an open tubular flute is to be playable and the octaves in tune, some conicity in the bore is necessary. This is one reason why the cylindrical Renaissance transverse flute and recorder had a more limited range than the Baroque forms, which had a conical body. When Theobald Boehm reinstated the cylindrical body on the transverse flute (see §4(iii) below), he introduced some conicity into the head joint (‘Boehm’s parabola’). A similar effect is produced on many other flutes by constricting the diameter of the distal end, often by boring a hole smaller than the diameter of the tube in the natural septum which closes the end of a tube of reed or cane.

Flute: 1. General

2. Classification and distribution.

Flutes are classified in the Hornbostel and Sachs system by the way in which the sound is generated and then by a variety of other criteria. Flutes are:
4 Aerophones
42 Wind instruments proper
421 Edge instruments or flutes, and thereafter
421.1 Flutes without duct, either
421.11 End-blown flutes (fig.1a–d), or
421.12 Side-blown (transverse) flutes (fig.1g, or
421.13 Vessel flutes (only those without a duct) (fig.1e). These are followed by:
421.2 Duct flutes, either
421.21 Flutes with external duct (fig.1h and j), or
421.22 Flutes with internal duct (fig.1f, i and k)

Within these main categories, further numbers are provided to indicate: whether the instruments are single or multiple and if multiple how arranged (whether the tubes of Panpipes, for example, are in a raft or a bundle); whether they are with or without fingerholes; or whether the distal ends are open, closed, a combination of both (as some panpipes are) or constricted, and if closed whether with a fixed stopper (as some organ pipes) or a movable stopper (such as a Pitchpipe or a Swanee whistle). Suffixes preceded by a hyphen are available to indicate the presence of air reservoirs (on the organ, for example) and whether the reservoir is rigid or flexible; and whether there are keys, keyboards or mechanical drive. The suffixes can, of course, be used in combination, so that a barrel organ could be 421.222.11/.31–62–9 (flutes (421) with internal duct in sets (.222) open ended without fingerholes (.11)/also closed ended without fingerholes (.31) with flexible bellows (–62) played mechanically (–9)) whereas a Boehm-system flute would be 421.121.12–71 (flutes (421) side-blown and single (.121) open-ended with fingerholes (.12) with keys (–71)).

There are very few parts of the world where the flute is unknown. One is Australia, where the only Aboriginal wind instrument seems to be the didjeridu. Another is Greenland, where the only instrument of the Inuit is said to be the frame drum. Whistles were certainly known in palaeolithic Europe, for pierced animal phalanges have been found at Magdalenian sites in France (fig.2), and it is improbable that bone antedated cane and reed, although of course bone survives far longer as a buried artefact (for further discussion, see Europe, pre- and protohistoric). Equally, it is hard to credit the assertion that no such use existed among the Inuit or the Australian Aborigines.

The most basic form of flute is a tube of reed or cane, stopped at one end and blown across the other. Such instruments, played in sets by a group of people (see Stopped flute ensemble), each playing a single note in turn in hocket style, are used in a number of areas, for example the skudučiai in Lithuania (see Lithuania, §II, fig.1) and the nanga of the Venda of South Africa.

More complex forms, with the tubes combined into a single instrument, are known as Panpipes and are found almost worldwide. The pipes may be arranged in a raft (fig.3b) or a bundle, although the bundle, found mainly in Oceania, is much less common. The pipes are usually arranged in scalar order, although zigzag patterns that suit the musical needs of a particular culture are also used: the best known example is the rondador of Ecuador. Also common is an interlocking arrangement, either with half the scale in each of the left and right ends of one raft, as in China or Japan, or divided between two instruments, as is frequent in South America. Rafts are frequently doubled: the sikus of Bolivia and neighbouring areas have one rank half the length of the other or one rank closed at the distal end and the other the same length but open. Both produce pitches in approximate octaves.

End-blown open-ended tubes with fingerholes are also widespread, especially throughout North Africa and the Middle East, most commonly under the name of Ney (fig.3a). The somewhat more elaborate Kaval is found in Turkey and the Balkans. A characteristic of all flutes is that when blown harder the pitch becomes sharper, and when blown more gently, flatter. With an end-blown flute, the player can compensate for this by altering the angle of blowing and thus covering the open end more or less with the lip – the more covered, the flatter the pitch. Thus the kaval and the ney are capable of great subtlety in performance, with infinite gradation of tuning and pitch.

The end-blown flute (sometimes called a rim-flute) normally has the rim chamfered externally to produce a better edge and thus aid production of the sound. A variant form has the chamfer at one point only, at the base of a U-shaped or V-shaped notch (fig.3c); the sides of the notch help to focus the airstream (see Notched flute). Notched flutes are found in Africa, the Pacific Islands, Central and South America, and East Asia. Among them are the Andean Kena, the Xiao of China and the Shakuhachi of Japan. A lacuna in the Hornbostel and Sachs system is the lack of any separate provision for the notched flute.

The end- and notch-blown flutes require considerable skill to produce a sound, for it is essential to maintain the correct angle of blowing and speed of airstream. An instrument on which the sound is easier to produce has the notch further down the tube, usually in the form of a rectangular mouth, and a plug almost closing the blowing end (for example, the Recorder). A narrow passage is left as a duct or windway to lead the air at the correct angle to the sharp edge at the base of the mouth (fig.1i). The player has only to blow, and a sound will always result. Thus the Duct flute is known almost everywhere; such instruments, however, lack the subtlety of tone control available on the end-blown flute.

Three variant forms of duct flute are more limited in distribution. The Indonesian Suling has an external duct, between a strip of leaf or bamboo and the head of the instrument (fig.1h), which is thinned in one section of its circumference to form the duct. In North and Central America, and in parts of East Asia, an internal plus external duct is found. The player blows into the end; a plug or a natural septum then forces the air out through a hole; and an external block, tied over the tube above the hole, channels the air along and then down into a mouth (fig.1j). Extremely elaborate blocks can be seen on flutes in pre-Columbian Mexican codices, and such flutes are still used in that area and in the southern USA. In another less common type, which appears in a number of areas, the player’s tongue forms the duct.

The number of finger-holes on flutes varies according to the needs of the music and the preferences of the culture. The most common number is six, to which is added, where necessary, a thumb-hole to aid overblowing to an upper register: heptatonic scales of various forms are the most frequent throughout the world. Chinese and some Southeast Asian flutes have an extra hole between the mouth-hole and the uppermost finger-hole which is covered by a thin membrane (a Mirliton) made from the inner lining of a piece of bamboo; this adds an enlivening buzz to the sound (see for example the Di of China). Chinese transverse flutes commonly have more holes than any others: a mouth-hole, a membrane hole, six finger-holes, two tuning vents and two holes for a decorative tassel which also functions as a suspension loop.

Some open-ended flutes have no holes at all. By opening or closing the far end with a finger, the player can produce the harmonics of either an open or a closed tube and, by interlocking these harmonics, can play melodically. An open tube would need to be a metre or more in length for this to be practicable, but a stopped tube which can also use some notes of the harmonic series of the open tube can be half that length or less. In the Highlands of Papua New Guinea one finds flutes 2 or 3 metres long but sounding only the overtones of the open flute (fig.3d); these are played in pairs, using hocketing techniques. In the Eastern Highlands, young men play shorter, very wide-bore flutes (often 10 cm or more in diameter) without finger-holes; pitch is varied by closing the open end more or less with the hand. Rather narrower flutes in Suriname and Guyana have a large hole in the side which is similarly used.

Otherwise flutes without finger-holes are usually regarded as whistles (see Whistle). But some whistles can produce more than one note, for example the boatswain’s pipe, on which the signals are varied by moving a hand over the airstream after it leaves the instrument (in Britain, in the Royal Navy, the instrument is the ‘call’ and the signals are the ‘pipes’). Whistles sometimes have one or two finger-holes. The one-hole whistle is a very common children’s toy, signal instrument, and bird-call imitator; the two-hole whistle is common in West and Central Africa, often with the holes in projections, one on each side near the top of the end- or notch-blown tube.

Whistles are blown in almost all the ways mentioned here, the most common being the end-blown and the duct. Many are more or less globular in shape, and vessel whistles and vessel flutes, sometimes called ocarinas (see Ocarina), are found in most parts of the world, made from natural seeds and gourds, or of pottery.

While most flutes are blown by mouth, a few, especially in Oceania and Southeast Asia, are blown by the nose (fig.3h). This is most commonly for cultic reasons, the breath of the mouth, which is used for eating and talking, being considered profane and the breath of the nose nearer to the soul (see Nose flute).

The least common flute worldwide is that best known in Western art music. The transverse flute is found in other cultures mainly in India, China, Korea, Japan and Papua New Guinea. Some other cultures in which it is well known today, for example that of the Indonesian island of Sulawesi, are known to have acquired it from European contact. In India it has been associated with Krishna, and, as the vamśa, is a favourite instrument for classical music. In the south it is quite a short instrument, around 30 cm in length, but in the north it may be twice that length or more. It is usually assumed that it was from India that the transverse flute migrated into Byzantium in the 10th century, at which period it began to appear in manuscript illuminations, and thus came into Europe.

In China the di, and before that the chi, were used. The latter was mainly a ritual instrument and the former was initially, as in Europe, a military flute eventually becoming an instrument for opera and later for all sorts of music. It is probable that the Korean transverse flutes derived from the Chinese, and it is certain that the Japanese instruments did, for Tang dynasty prototypes are preserved in the Shōsōin (the imperial treasury of Emperor Shōmu, d 756) in Nara.

In Japan the ryūteki and other transverse flutes are, with the cylindrical oboe hichiriki, the main melody instruments of the ritual court music, gagaku. The Nōkan, which is thought to have derived from the ryūteki, is the most important melody instrument of the nō theatre and is also widely used in other genres.

It is clear that all the East Asian transverse flutes derived from the Chinese; whether there is any connection between the Chinese and the Indian is not known, although as with many other instruments, the di is thought to have come into China from western areas. Certainly, however, the ‘sacred flutes’ of Papua New Guinea are of independent origin. Some are short, 30–50 cm in length, and often played in groups; the most impressive are up to 3 metres long and are used in pairs, one a note higher than the other. They sound only natural harmonics, hocketing an interlocking series a tone apart.

There is no evidence of the transverse flute in ancient Egypt. The end-blown flute was common there, as in Mesopotamia, from the earliest times; because such instruments were held obliquely, as they almost invariably still are, they have often been misinterpreted as transverse instruments, for example the one on a slate palette in the Ashmolean Museum illustrated by Hickmann (1961). The transverse flute was unknown also in ancient Greece (a statue illustrated by Wegner (1963) is a fragmentary late Roman copy with a very small piece of something next to the figure’s mouth; there is no evidence that this is the remains of a flute). One well-known late Etruscan relief of the late 2nd or early 1st century bce, carved on an urn or sarcophagus in the tomb of the Volumnii family near Perugia, has been identified as the first European illustration of a transverse flute (fig.4). There is no other evidence for the transverse flute in Etruria or Rome, whereas there is frequent evidence for the plagiaulos, a reed instrument played transversely; thus, while the Volumni relief does look much like a transverse flute, it should be regarded with some suspicion. The Roman bone tubes made in short sections, each with one or two holes in the side, which have often been described as flutes – ignoring the difficulty of assembling such fragments into a single tube – have more recently been recognized as hinges.

Flute