Flute: History, Construction and Sound

Dark wooden transverse flute with gold rings and gold keys lying horizontally below its matching rosewood case with a gold inlaid cartouche, on a light grey background. — Flute by Jean-Louis Tulou, French, about 1852, with case, Metropolitan Museum of Art. Photo: Jean-Louis Tulou (maker); photograph by The Metropolitan Museum of Art, CC0. Image credit

The modern concert flute is a long, narrow metal tube played sideways, sounded by directing a stream of air across a hole near one end. It has no reed, which is why it is classed as an edge-blown flute and not a reed woodwind. Its form comes from Theobald Boehm’s designs of the 1830s and 1840s, which reorganised holes and keys for accuracy of pitch. Related side-blown flutes of bamboo, wood and bone appear in musical traditions across Asia, Europe and beyond.

Forty thousand years of blowing across a hole

Flutes of bone and ivory, found in caves in southern Germany, are dated to roughly 40,000 years ago, among the oldest known musical instruments. Those early flutes are not the direct ancestors of the modern orchestral flute, but they show how old the principle is: a sharp edge splits an air stream, and a tube of air resonates. Flutes held sideways turn up in many places, including East and South Asia, where bamboo transverse flutes have long histories, and in medieval Europe. Precisely where and when the sideways form began is uncertain.

European makers of the Renaissance built simple wooden flutes, cylindrical and usually with six finger holes. In the Baroque period they developed a conical bore, made in several joints, typically with a single key for a difficult note. A London flute of around 1765 in Yale’s collection, made of boxwood with rings of ivory and one silver key, is of this kind. The flute became fashionable among amateurs, and by 1829 a London periodical could remark that it took for granted that one man in ten played it.

Theobald Boehm’s rearranged holes

A flute player fingers in ways that depend on where the holes are. On older flutes the holes were small and set where the fingers could reach, so pitch and loudness suffered. Theobald Boehm, a Munich goldsmith and flute player, reconsidered the layout acoustically, placing holes where the physics required and covering them with padded keys linked by rods and rings. He introduced a ring-key flute in 1832 and, by 1847, a further design with a cylindrical bore and a separate parabolic head joint, the design from which today’s flute descends.

The instrument is still made in three parts: a head joint with the embouchure hole, a body carrying most keys, and a foot joint. The tube is usually nickel silver, silver, gold or platinum; wooden flutes are still made for some purposes. Together the parts are about 66 centimetres long. Keys may be closed, or open-hole with small holes the fingertips cover, which permit some special effects. The foot can end at C or extend one note lower to B.

An air jet against an edge

The player’s lips form a narrow stream that strikes the sharp edge of the embouchure hole. The stream flips alternately into and outside the tube, and the pulsing drives the column of air inside. Closing or opening the holes changes the effective length and hence the pitch. Overblowing, that is, blowing harder and more tightly, makes the air column vibrate in halves, then thirds, and raises the pitch by an octave and beyond without changing the fingering pattern.

Because nothing vibrates but air and a little breath noise, the tone is pure, with few strong overtones in the lowest octave and more brightness above. Breath control gives expressive vibrato, and tonguing with the tip of the tongue gives a crisp start to notes. Single, double and triple tonguing allow fast repeated notes, and flutter-tonguing rolls the tongue or throat for a growling effect. Quiet low notes are easily covered by an orchestra, and the top octave can cut through a full ensemble.

Three octaves and their colours

The standard flute, in C, runs from middle C (C4) up to about C7, with the option of a B3 below; skilled players can go a little higher. It is non-transposing, so the notes sound as written. The Philharmonia Orchestra gives its frequency range as about 261 hertz to 2.1 kilohertz. Piccolo, at half the length, sounds an octave above the written pitch, while the alto flute in G and the bass flute are lower relatives.

Each octave has its own colour. The bottom register is soft, breathy and dark, and is easily masked. The middle octave is clear and singing, the sound most people associate with the flute. Above that, the tone grows brilliant and strong and is harder to play softly or in tune. Composers exploit these differences, using the darker lower notes for a sensuous quality, as in the solo that opens Debussy’s Prélude à l’après-midi d’un faune, and the top for sparkle.

A posture that invites the ear

The flute is held out to the right, horizontally, supported by the left index finger, the right thumb and the chin or lower lip. Both shoulders and the neck must stay relaxed, and the head rotates slightly as the flute is brought to the lips. Fingers press keys and close rings; the little fingers work keys for the lowest and some alternate notes. The embouchure is fine-tuned by rolling the flute slightly toward or away from the mouth, adjusting pitch and brightness.

Breath management is the central discipline. A flute uses a lot of air per note, because much of it escapes across the hole and does not enter the tube. Players learn to plan phrase lengths around breaths and to take air quickly through the mouth. Fingering patterns for trills and rapid passages are learned from charts, and alternate fingerings, variations in which different holes are closed, correct pitch and ease technical difficulties.

Older flutes and other side-blown flutes

Before Boehm, the nineteenth century produced many competing keywork schemes, and makers in London and elsewhere built flutes of wood, ivory or metal. A flute by Rudall and Rose made in London between 1847 and 1850, now in the Victoria and Albert Museum, shows early adoption of Boehm’s ideas in cocus wood with nickel-silver keys. Research at Duke University argues that the Boehm system won acceptance only gradually, against rivals, rather than triumphing at once.

Elsewhere the transverse flute has its own traditions. The Chinese dizi is a bamboo flute with an additional hole covered by a thin membrane, which adds a buzzing brightness to the sound. The Indian bansuri is a simple bamboo flute central to Hindustani music, and Japanese fue flutes serve in court, festival and theatre traditions. Irish traditional players use simple-system wooden flutes of a design close to the nineteenth-century instrument.

Orchestra, quintet and beyond

In the orchestra the flute belongs to the woodwind section, typically with two or three players, one often doubling on piccolo. The flute shares the woodwind family with the Oboe, Clarinet and Bassoon, and in the wind quintet it sits above the others, often carrying the melody. Solo repertoire includes Bach’s sonatas, Mozart’s concertos, Debussy’s Syrinx for unaccompanied flute and a large twentieth-century body of works for the instrument.

Jazz flutists often double on Saxophone, and flute also appears in folk ensembles, Latin dance bands and popular recordings. Flute choirs, in which groups of flutes from piccolo to bass play together, have become a separate ensemble type. Military and concert bands use the flute and piccolo for high melodic lines that sit above the clarinets, and the Harp pairs with it in Mozart’s concerto for the two instruments.

Keeping pads seated and tube clean

Breath carries moisture into the tube, so a flute is dried after every session with a soft cloth or swab drawn through the body. The outside is wiped with a soft cloth to remove skin oils, which can dull or corrode the finish. The head-joint cork, which sets the position of the reflecting end of the tube, affects tuning and is checked by a technician. Flutes should be stored in their case away from heat, sunshine and sudden temperature changes.

The keywork is delicate; a bent rod can make pads fail to seal, and the flute should always be assembled by holding the body and head, not gripping the keys. Pads compress and wear, and a repairer replaces and adjusts them every few years or as needed. Wooden flutes require additional care to avoid cracking, including gradual warming before play and periodic oiling.

Odd facts and curiosities

A flute made in London by Rudall and Rose between 1847 and 1850 has a head joint replaced later by a successor firm, which stamped its own London address on it.
Theobald Boehm worked as a goldsmith and metalworker as well as a flute player, which may help explain his move to metal tubes.
The Chinese dizi has a hole between the embouchure and the finger holes that is covered with a thin membrane.
The piccolo is roughly half the length of a flute and sounds an octave higher than written.
The oldest surviving flutes may be around 40,000 years old and were cut from bird bone and mammoth ivory.

Terms used in this entry

Boehm system: A key and hole arrangement devised by Theobald Boehm in the 1830s and 1840s, now standard on flutes and adapted to other woodwinds.
embouchure: The shape and position of the lips, jaw and facial muscles used to direct the air stream across the mouth hole.
flutter-tonguing: A technique in which the player rolls the tongue or throat while blowing, to produce a rapid, growling flutter.
foot joint: The bottom section of the flute, extending the range down to C or B.
head joint: The top section of the flute, containing the embouchure hole and a cork that seals the end of the tube.
open-hole key: A key with a hole in its centre that the fingertip seals directly, allowing some special effects.
overblowing: Blowing harder and more tightly so the air column vibrates in fractions, sounding a higher note without changing the holes that are open.
transverse: Held sideways, across the player’s body, in contrast to flutes that are held pointing downward and blown at the end.