This article pertains to the musical instrument. For the sailing ship class that has a variant spelling using this word, see Fluyt.
The flute is a musical instrument of the woodwind family. Unlike other wind instruments, a flute produces its sound from the flow of air against an edge, instead of using a reed. A musician who plays the flute is sometimes called a flutist or flautist.
Flute sounds are typically open and hollow as a result of relatively weak upper partials. As a result, flute tones are sweet in character and blend well with other instruments. The flute's timbre, pitch and attack are flexible, allowing a very high degree of instantaneous expressive control.
Categories of flutes
A flute is an extemely widespread instrument around the world, which can be attributed to its simplicity and pleasing sound. A flute made from a mammoth bone, found in the Swabian Alps and dated to 30,000 to 37,000 years ago is the oldest known musical instrument.  (http://www.cbc.ca/story/arts/national/2004/12/30/Arts/flute-prehistoric041230.html) At its most basic, a flute can be an open tube which is blown like a bottle. Over time, the increasing demands of musical performance have led to the development of what many people consider the flute, the Western concert flute, which has a complex array of keys and holes.
There are several broad classes of flutes. With most flutes, the musician blows directly onto the edge of the flute. However some flutes, such as the recorder, whistle, and ocarina have a duct that directs the air onto the edge. This makes the instrument easier to play, but takes a degree of control away from the musician. Usually fipple flutes are not referred to as flutes, even though the physics, technique and sound are similar.
Another division is between side-blown (or traverse) flutes, such as the Western concert flute, piccolo, fife, and bansuri; and end-blown flutes, such as the recorder, ney, kaval, and shakuhachi. The player of a side-blown flute uses a hole on the side of the tube to produce a tone, instead of blowing on an end of the tube.
Playing the zampoņa
, an Inca
instrument and type of pan pipes.
Flutes may be open on one or both of their ends. The ocarina, pan pipes, concert whistle, jug, police-whistle, and bosun's whistle are closed-ended. Open-ended flutes such as the concert flute and recorder have more harmonics, and thus more flexibility for the player, and brighter, more pleasing timbres. An organ pipe may be either open or closed, depending on the sound desired.
Flutes can be played with several different air sources. Conventional flutes are blown with the mouth, although some cultures use nose flutes. Organs are blown by bellows or fans.
A flute produces sound when a stream of air directed across the top of a hole bounces in and out of the hole. Some engineers have called this a fluidic multivibrator, because it forms a mechanical analogy to an electronic circuit called a multivibrator.
The stream beats against the air in a resonator, usually a tube. The player changes the pitch of the flute by changing the effective length of the resonator. This is done either by closing holes, or more rarely, with a slide similar to a trombone's slide.
Because the air-stream is lower mass than most of the resonators used in instruments, it can beat faster, but with less momentum. As result, flutes tend to be softer, but higher-pitched than other sound generators of the same size.
To be louder, a flute must use a larger resonator, and a wider air-stream. A flute can generally be made louder by making its resonator and tone-hole wider. This is why police whistles, a form of flute, are very wide for their pitch, and why organs can be far louder than concert flutes: an organ pipe's tone-hole may be several inches wide, while a concert flute's is a fraction of an inch.
The air-stream must be flat, and precisely aimed at the correct angle and velocity, or it will not vibrate. In fippled flutes, a precisely machined slot extrudes the air. In organs, the air is supplied by a regulated blower.
In non-fipple flutes, especially the concert flute and piccolo, the player must form and direct the stream with his lips. This makes the transverse flute's pitch and timbre more instantly expressive than any other instrument. However, it also makes the transverse flute immensely more difficult to play than the recorder.
Generally, the quality called "tone color" or "timbre" varies because the flute produces harmonics in different intensities. A harmonic is a frequency that's an even multiple of the lowest, or "fundamental" tone of the flute. When a flute sounds harsh, or whiny, it is being played to provide more harmonics. Generally the air-stream is thinner (to vibrate in more modes), faster (providing more energy to vibrate), and aimed across the hole more shallowly (permitting a more shallow deflection of the airstream to resonate).
Almost all flutes can be played in fundamental, octave, tierce, quatre and cinque modes simply by blowing harder and making the air-stream move more quickly and at a more shallow angle. Flute players select their instrument's resonant mode with embouchure and breath control, much as brass players do.
The timbre is also affected by the quality of the resonator. Generally, more rigid resonators (such as wood) have a "dead" sound, because they have a higher acoustic impedance, and do not resonate with the harmonics. Concert flutes are expected to produce a "brilliant" sound, with a wide range of harmonics. To help this, they are thin tubes made of hard-drawn silver or gold alloys. These are more mechanically elastic than wood, and therefore vibrate in more modes. Theoretically, flutes constructed in thin tubes of elastic but heavy metals, such as alloys of gold, tungsten, platinum or osmium sound "richer" because they vibrate to a lower, therefore more audible range of harmonics. This effect also explains the good tone of bronze and brass flutes, which are less massive, but more elastic.
The Western concert flutes
The Western concert flute is a traverse flute which is closed at the top. Near the top is the tone hole, which the player blows against. The flute has circular finger holes, which can be used to produce high and low sounds depending on which finger holes are opened or closed.
The standard concert flute is pitched in C and has a range of about 3 and a half octaves starting from middle C. Also commonly used in orchestras is the piccolo, a small flute usually pitched an octave above the concert flute. Alto and bass flutes, pitched a fourth and an octave below the concert flute, are used occasionally. Parts for the alto flute are more common than for the bass. Many other sizes of flute and piccolo are used from time to time. A much-less common instrument of the current pitching system is the treble G flute. An older pitching system, used principally in older wind-band music, includes D-flat piccolos, E-flat soprano flutes (the primary instrument, equivalent to today's concert C flutes), F alto flutes, and B-flat bass flutes.
The modern professional concert flute is generally made of silver, gold, or combinations of the two. Student instruments are usually made of nickel silver, or silver-plated brass. Wooden flutes and headjoints are more widely available than in the past.
- Theobald Boehm, The Flute and Flute-Playing (Dover Publications, 1964)
by Theobald Boehm
- James Phelan, The Complete Guide to the Flute and Piccolo (Burkart-Phelan, Inc., 2004)
By James Phelan
- Nancy Toff, The Flute Book (Charles's Scribners Sons, 1985)
The Development of the Modern Flute By Nancy Toff
- Tai Hei Shakuhachi - Japanese Bamboo Flutes (http://www.shakuhachi.com)
- Shakuhachi Headjoint for the Silver Flute (http://www.shakuhachi.com/Q-Models-Headjoint.html)
- Flutes.tk (http://www.flutes.tk)
- FluteInfo (http://www.FluteInfo.com)
- LarryKrantz.com (http://www.larrykrantz.com)
- Flute Acoustics (http://www.phys.unsw.edu.au/music/flute/)
- The Virtual Boehm Flute (http://www.phys.unsw.edu.au/music/flute/virtual/main.html) gives an immense database of standard and alternative fingerings, including quarter-tones and multiphonics.
- FluteHistory.com (http://www.flutehistory.com)
- Dayton C. Miller Flute Collection (http://memory.loc.gov/ammem/dcmhtml/dmhome.html) The Dayton C. Miller flute collection has many pictures of flutes through the ages, among other useful information.