Wind Chest And Pipes Of Small Organs example essay topic

HISTORY AND ORIGINATORS OF KEYBOARD BAROQUE PERIOD Harpsichord (Italian cembalo; French clave cin), stringed keyboard instrument in which the strings are plucked to produce sound. It was developed in Europe in the 14th or 15th century and was widely used from the 16th to the early 19th century, when it was superseded by the piano. In the 20th century the harpsichord was revived for performance of music of the 16th, 17th, and 18th centuries, as well as for new compositions. The incisive sound quality of the plucked metal strings adds clarity to melodic lines. The harpsichord is particularly effective in performing contrapuntal music-that is, music that consists of two or more melodies played at the same time, such as that of the German composer Johann Sebastian Bach. Construction and Mechanism The harpsichord usually has a wing-shaped body, or case, like a grand piano; however, its proportions are narrower and longer, and the case and its inner bracing are normally lighter.

Harpsichords have also been built in other shapes. These include the virginal, or virginals, a small oblong instrument; the spinet, a small polygonal harpsichord; and the less common clavicytherium, an upright harpsichord. From the 16th to 19th century the terms spinet and virginal were often used interchangeably, and in England during that era any harpsichord was called a virginal. Harpsichords of any shape have the same plucking mechanism. For each string a small piece of material, or plectrum, is set in a thin slip of wood, or "jack", which rests internally on the far end of the key. When the front of the key is depressed, the far end rises, and the plectrum plucks the string.

The jack is pivoted so that, when the key returns to rest position, the plectrum slides by without striking the string. Since the volume and tone of the sound produced by the plucking mechanism remain constant regardless of the forcefulness of the keystroke, various methods have been developed to alter the harpsichord's sound. Many harpsichords have two strings for each key, with a row of jacks for each set of strings. Stops, or registers, allow the player to move unwanted sets of jacks slightly out of reach of the strings, thus making possible different volumes and combinations of tone colors.

One set of strings may sound an octave above normal pitch. Some 18th-century German harpsichords had a set of strings sounding an octave below normal pitch. Harpsichords often have two keyboards, or manuals, which can usually be coupled or used separately, allowing further variations of tone color and volume. A typical two-manual harpsichord of the 18th century had strings at normal and octave-high pitch playable on the lower manual, strings at normal pitch controlled by the upper manual, and a coupling mechanism.

Early History The earliest school of harpsichord building developed in Italy in the 16th and 17th centuries. Italian harpsichords differed from others in that they normally were made of extremely thin wood and then placed in a stronger outer case of the same shape. A second important school of building developed in the 16th and 17th centuries in Flanders, centered around the influential Rockers family of builders. These schools gave way in the 18th century to distinctive styles of building that developed in France (the Blac het family), Germany (the Hass family), and England (Jacob Kirkman).

Harpsichords of the different national schools varied in details of their proportions and construction, resulting in slight, although characteristic differences in tone color. Modern Developments In the 20th century, two broad approaches to harpsichord building emerged. The first utilized recent principles of construction, such as are found in present-day pianos. Stimulated by the Polish harpsichordist Wanda Landowska, this style was exemplified by the French piano firms of Ple yel and 'Erhard. Their harpsichords relied on heavy strings under high tension in a heavily braced case.

Many 20th-century harpsichord works were written for such instruments. Other builders sought to relearn historical principles of proportion and construction in an effort to duplicate the sound of historical instruments. Stimulated by the German-English builder Arnold Dolmetsch and exemplified by Martin Skowroneck, a German, this school relied on light stringing in a highly resonant case. American builders in this style include William Hyman, Frank Hubbard, and William Dowd. American instrument maker John Challis employed a different, more modern approach to construction of the instrument. Though he based the decorative scheme of his designs on Dolmetsch's works, Challis experimented with new techniques and materials, such as metal and plastic, to produce harpsichords that were better adapted to the extreme climate changes in North America and maintained a rich tone quality.

Organ, keyboard musical instrument in which compressed air vibrates within tuned pipes to produce sound. An organ consists of flue pipes and / or reed pipes, an air supply, and the keys and other controls. Pipes Flue pipes are made of metal or wood, and they work much like whistles. Air enters at the foot of the pipe, moves as a sheet against a narrow slit or flue, and begins to vibrate as it passes across a sharp lip set in the pipe above the flue. This initial vibration causes all the air in the pipe to vibrate, producing a musical tone. The pitch of the tone depends on the length of the pipe; the shape and material of the pipe influence the color or quality of the tone.

Some flue pipes are closed at the top; "stopped" pipes produce pitches an octave lower than open pipes of the same length. In reed pipes, the reed and the metal trough against which it beats (called a shallot) are encased in a pipe into which air is released from the air supply. The incoming air causes the curved end of the reed to beat against the shallot and set the surrounding air into vibration. The musical pitch produced is low for long reeds, high for short reeds.

The shallot is connected to a pipeline resonator, the shape of which affects the color of the sound. A set of pipes all having the same tone quality is called a rank. The most characteristic organ sound is produced by metal flue pipes called diapasons or principals; pipes of this kind form the central core of classic organ sound. Because the lowest note on most organs (two octaves below middle C) is produced by an open diapason pipe about 8 ft long, ranks of pipes abnormal pitch are spoken of as 8-ft ranks. Ranks sounding an octave lower than normal are called 16-ft ranks, and those sounding an octave higher, 4-ft ranks. Mutations are ranks of pipes sounding at pitches other than octaves above normal pitch, such as an octave and a fifth above normal (for example, two G's above a C).

Mixtures are ranks of pipes of different pitches operated as a single unit (by a single stop). Mixtures often contain ranks sounding several octaves above 8-ft pitch as well as mutation ranks. The high pitches of mutations and mixtures blend together to produce the incisive, bright quality that is associated with organ sound. On large organs the ranks are grouped together into several divisions, each controlled by a separate keyboard, or manual, and having one or more wind chests, airtight boxes that act as air reservoirs. The main division is called the Great Organ; the other most common divisions are the Choir Organ, the Swell Organ, and the Pedal Organ. The pipes of the Swell Organ are enclosed in a "swell box", a chamber having a slat-covered opening similar to a venetian blind.

The slats can be opened and closed by a pedal lever, allowing gradual changes in volume. Air Supply The air for the pipes is supplied from a wind chest, on which the pipes are mounted. Air, which is produced by bellows or by an electrical blower, enters the wind chest at a constant pressure. Controls When a key is depressed, small valves open to allow air from the wind chest to enter the pipes and cause them to sound. A "stop" mechanism allows any rank of pipes to be prevented from sounding. The ranks are controlled by knobs or switches (called stops) set near the keyboard.

By extension, the ranks of pipes they control are sometimes called stops. Until the 19th century the connections linking the keys and pipe valves-including mechanisms to couple keyboards so that ranks of pipes may be multiply controlled-were achieved mechanically by a system of levers and cranks connected by strips of wood called trackers and stickers. Builders in the 19th century began to devise electrical and pneumatic actions to make the key-to-valve and stop connections. Because many organists believe these actions to be less responsive and sensitive than direct mechanical linkages, in the 20th century organs were again being built with the traditional tracker action. The keyboards, wind chest, and pipes of small organs are contained in one unit. In large organs the keyboards and other controls are built in a separate unit called the console.

Many organ consoles have a number of controls, called pistons, which allow the organist to bring into play at one stroke a combination of several ranks or stops. Each organ is unique in that it must suit the acoustics and architecture of the room that houses it. The room itself has an intimate acoustic relation to the organ, profoundly influencing the sound of the organ by the amount of reverberation it allows. History The earliest organ, the hydraulic, was developed by the Greek inventor Ctesibius (flourished 3rd century BC). It utilized a large chamber partly filled with water.

The wide mouth of a funnel-like extension from the wind chest was set in the top of the water; as air pressure in the wind chest fell, water rose in the funnel and compressed the air, thus keeping the air pressure constant. The hydraulic was used for public entertainments in ancient Rome and Byzantium. Bellows-type organs were also known to the ancient world. This was the organ that reappeared in Europe in the 8th and 9th centuries, imported from Byzantium and from Arabs who had discovered ancient Greek treatises. Although some ancient organs had a stop mechanism, this device was forgotten, and on early medieval organs all ranks sounded at once, creating a formidable effect.

By the 15th century the stop mechanism had been reinvented, pedal keyboards came into common use, and reed stops (not found on ancient organs) were developed. Smaller organs had also become common: the portative organ, carried by a strap around the player's neck, which had only one rank of pipes and was supplied with wind by a small bellows pumped by the player; the positive organ, self-contained and portable; and the regal, a small instrument with one rank of nasal-sounding reed pipes. Between 1500 and 1800, various national styles of organ building developed, each distinguished by characteristic-sounding ranks. German organs of the 17th and 18th centuries were particularly outstanding, and it was for such organs that the music of Johann Sebastian Bach was written. Organ builders in the 19th century devoted much effort to developing pipes that imitated the sound of orchestral instruments. About the same time, the swell box came into use.

These innovations, which the best builders integrated with the traditional features of earlier organs, stimulated the organ works of such composers as the Hungarian Franz Liszt, the Belgian C'ear Franck, the German Max Reger, and, in the 20th century, the French composer Olivier Messiaen. Many 19th-century organs, however, concentrated principally on stops imitating the orchestra and were used for music that was basically orchestral in origin or conception. In the 20th century a movement occurred to revive 18th-century instruments, often incorporating the best of the 19th-century innovations. Electronic Organs Electronic and electric organs, developed in the 20th century, are not organs in the strict sense, for they do not produce sound by air vibrating in a pipe; rather, they are instruments in their own right. One kind, invented in 1935 by an American, Laurens Hammond, utilizes electrical circuits and amplifier's to produce and enlarge the sound. Another kind uses electronic devices such as vacuum tubes.

Although such instruments are often designed to imitate the tone qualities of pipe organs, they are frequently criticized for a pinched or artificial-seeming sound. Electronic organs were widely used in the rock bands of the 1960's and after. In such bands, which use extensive electrical sound amplification and manipulation, the distinctive qualities of electronic-organ sound are exploited for their own sake. Reed Organs Keyboard instruments in which the wind supply is directed toward free metal reeds like those of a harmonica or accordion are called reed organs.

They include the melodeon, developed in the United States about 1825, and the harmonium, developed in Germany about 1810.