Musical Instruments

V

Membranophones

All true drums belong to the membranophones. A drum has one or two heads of skin or plastic stretched over a resonator or over a narrow frame. Kettledrums, having a single head over a bowl-shaped resonator, are produced in all sizes. Orchestral kettledrums are tuned by means of hand screws or pedals, whereas some non-Western types are tuned with paste or heat applied to the head, or by manipulating the lacing which attaches to the head or heads. Hard and soft beaters offer tonal variety. In India the technique of playing small kettledrums (the baya in the pair called tabla) with the hands is a subtle art.

Cylindrical drums, usually unpitched, vary in size from huge basses drawn on wagons in parades, to shallow, waist-slung drums equipped with snares that intensify the sound. In parts of Africa and the Pacific Islands sacred drums are taboo to the uninitiated; their wood bodies are elaborately carved and decorated, and revered drums occupy huts to which votive offerings are brought. Slender, elongated drums with reptile-skin heads glued on with human blood accompany male ritual dances in New Guinea.

Some Native Americans accompany tribal dances and chants on broad, shallow drums beaten by several players at once. A light hand-held frame drum is played by Eskimo shamans; it resembles Asian shamans' drums. The tambourine is a frame drum that usually has rattles attached to the frame; it is both struck and shaken and is sometimes rubbed.

The rommelpot is a Flemish friction drum played as a toy; rubbing a stick or string protruding through its head causes the head to vibrate. A more important membranophone is the mirliton. Not actually an instrument in its own right, but rather a tone modifier, the mirliton is a thin membrane attached over a hole in a resonator, adding a buzzing quality to the sound. One popular mirliton, the kazoo, disguises the voice. Other mirlitons enrich the tone of instruments as diverse as African xylophones, drums, and Chinese flutes.

---

---

VI

Aerophones

Among aerophones, several different methods are used to set the air in vibration.

A

Flutes

In flutes a wind stream impinges on an edge, setting up eddies in an enclosed body of air. The wind may come from the player's lungs, a bellows or squeezed windbag, or a mechanical fan. If the resonator enclosing the air is a tube, its length determines the pitch; usually, tone holes in the tube wall are opened or closed to change the sounding length and, hence, the pitch.

In the orchestral flute the lips direct breath against the edge of a mouth hole in the tube wall; such flutes are called transverse, or side blown (see Flute). The Japanese shakuhachi is blown against the sharpened rim of one end. A panpipe is also end blown; each of its pipes gives a different note, according to its length. Some end-blown flutes are blown through one nostril; such “nose flutes” are often considered magical.

In whistles and recorders an internal duct aims the breath against the edge of a hole in the wall; the flue pipes on an organ thus operate like one-note whistles. Some Native American flutes have a duct on the outside of the tube, a system unknown otherwise. The ocarina, a popular ducted flute invented in Italy (about 1860), has a globular resonator rather than a tubular one, giving it a hollow, dark tone. In general, the shape of an aerophone's resonator has a more critical effect on timbre than does its material, because the resonator walls vibrate little, compared to the air within.

B

Single and Double Reeds

Among reed-vibrated aerophones, the clarinet, saxophone, and their relatives employ a single broad reed of springy cane fastened at one end over a hole in a mouthpiece. The reed responds to breath pressure by beating against the hole many times per second, allowing puffs of wind into the tube to vibrate the enclosed air. The brass-reed pipes of an organ are of this type.

The oboe, bassoon, shawm, and other double-reed instruments produce sound when two slender blades of cane pinch together rapidly, thus interrupting the wind stream passing between them into the resonator. Whereas clarinets have a more-or-less cylindrical tube, oboes have a conical pipe; the different internal shapes foster distinctive patterns of harmonics that give these instruments their characteristic timbres.

C

Free Reeds and Other Instruments

In free-reed aerophones such as the mouth organ, or harmonica, the accordion, and reed organs (harmonium, melodeon), many brass reeds of graduated size produce the sounds. Under wind pressure each reed vibrates back and forth through a close-fitting aperture. Because the length and shape of each free reed determines its pitch and timbre, no resonator is required; the reed vibrates air in the atmosphere. All Western free-reed instruments evolved from the Oriental mouth organ with multiple pipes (such as the Chinese sheng and the Japanese sho), introduced into Europe in the 18th century.

The bull-roarer, a tapered wood blade whirled around on a string, also vibrates the atmosphere directly without benefit of a resonator. Its unpitched rumble sounds powerful and mysterious. The jew's harp has a twangy tone that arises when the stiff metal or cane reed is plucked in front of the mouth and vibrates the air within.

	More from Encarta
	•  Presidential Myths Quiz •  Coffee break: Recharge your brain