Percussion instruments

[Fr. instruments a percussion (of the orchestra, batterie); Ger. Schlaginstru-ment, Schlagzeug; It. percussione; Sp. percusion, ba-teria]. Musical instruments that produce sound by being struck or, less often, scraped, shaken, or plucked. In more formal classifications of musical instruments, they are usually divided between mem-branophones and idiophones, with both categories including instruments of definite as well as indefinite pitch.

 

Idiophone. Any musical instrument that produces sound by the vibration of its own primary material, i.e., without the vibrations of a string, membrane, or column of air. Idiophones make up a very diverse collection that is broken down further according to construction and playing technique.
 

1. Concussion idiophone. Two sonorous objects are struck together: castanets, claves, cymbals.

2. Percussion idiophone. A sonorous object is struck with a nonsonorous object: bell, celesta, gong, metallophone, slit drum, xylophone.

3.  Rattle. Objects are shaken together or are shaken against a sonorous object: angklung, maraca, pellet bell.

4. Scraper. A stick is drawn over a notched object: cog rattle, guiro, washboard, yu.

5. Plucked idiophone (lamellaphone, linguaphone). A flexible tongue, fixed at one end and free at the other, is plucked: ew’s harp, mbira, music box.

6. Friction idiophone. An object is made to vibrate by rubbing: glass harmonica, musical saw.

Membranophone. An instrument in which sound is produced by the vibration of a membrane, traditionally a stretched animal skin, though now often a synthetic material. Most are drums, but mirliton instruments are also included in this category. The membrane may be made to vibrate by striking, rubbing (friction drum), or, in a mirliton, by the action of sound waves.


 

Bell

(1) Any of a variety of objects that, when struck, emit a ringing sound. There are three basic types of bell: open, cup-shaped bells, usually made of metal, that are struck at the rim; closed, spherical pellet bells; and tubular bells (orchestral chimes). Only the first type is discussed here.
 

Open bells may be hemispheric, quadrilateral, or beehive-shaped, but the characteristic bell of the Occident is tulip-shaped or “campaniform,” with a well-defined shoulder and flaring sides. Quadrilateral bells (e.g., the cowbell) are typically made of sheet metal, hammered and soldered. Other metal bells are cast, most often of bronze. The smallest bells, such as those hung on clothing or animal harnesses, may weigh only a few grams. The largest bell ever cast weighed approximately 200,000 kg. Church tower bells generally weigh from 4,000 to 10,000 kg., though a few approach 20,000 kg. (44,000 lb.).
 

Bells are struck either from the inside by a clapper or from the outside by a hammer or a mechanical striking device. Chiming consists in swinging a bell so as to cause the clapper to strike it. Ringing consists in rotating a bell vertically through a full circle, causing the clapper to strike it more forcefully. Clocking consists in moving a bell’s clapper so as to cause it to strike the stationary bell.

A bell produces a complicated, nonharmonic vibrational pattern. A bell can be tuned, however, so that its five lowest partials approximate a familiar chord. This is done for each partial by removing metal from a specific part of the bell after casting, causing the pitch of the partial in question to be lowered. The fundamental is the strongest pitch; the hum tone lies an octave below the fundamental, and the nominal an octave above; the tierce is a minor third and the quint a perfect fifth above the fundamental. In addition, there are many untuned higher partials and a momentary strike note lying near the fundamental. This pattern of vibrations characterizes only the large, tulip-shaped bells of the Occident. Cowbells, hemispheric bells, the bells of the Far East, and handbells have considerably different patterns.
 

Bells are ancient and widely distributed. Chinese bells can be dated back to before 1500 B.C.E., and the Chinese knew how to tune bells as early as the 5th century c.E. Multiclapper wooden bells and metal pellet bells from the 8th to 10th centuries have been excavated in South America. In the Far East, large, single bells and sets of tuned bells (bell chimes) have been associated since ancient times with religion and temple worship. Both handbells and tower bells have been associated with Christian worship from about the 5th century. The craft of bell casting and tuning developed in Europe between the 12th and 14th centuries. Sets of large bells were installed in towers on top of or next to churches and were rung to mark the hours, to call people to worship, to signal emergencies, and to toll for the dead. Bell wheels and mechanisms for ringing bells automatically were introduced in the 14th century. The carillon (a set of tuned bells operated by a keyboard mechanism) was developed during the 15th and 16th centuries in the Low Countries. In England, the practice of change ringing arose during the same period. Bell manufacture was an empirical art until the late 19th century, when bell acoustics were investigated scientifically.
 

(2) [Fr. pavillon; Ger. Schallbecher, Schallstiick, Schalltrichter, Sturze; It. padiglione, campana; Sp. pabellon, campana] The opening of a wind instrument at the end opposite the mouthpiece. The flaring bells of  brass instruments serve two acoustical purposes: they alter the vibrational modes of the air column, making them approximate more closely the harmonic series, and they reinforce certain partials, thus molding the tone color of the instrument. The bell of a woodwind affects primarily the tone color of only those pitches produced with most or all of the finger holes closed, since for other pitches much of the sound is radiated through the open finger holes.