From Academic Kids
This sound differs in several respects from other keyboard instruments. In particular:
- The sound output is continuous, rather than decaying, i.e. the sound of the organ usually continues for as long as a key is held down. In terms of ADSR envelope, the organ usually has infinite sustain.
- The change to the sound (particularly the amplitude of the sound) usually depends on how far down a key is pressed, rather than how hard the key is struck (as with a piano, celesta, clavichord or harpsichord, all of which are velocity sensitive), while the organ is displacement sensitive rather than velocity sensitive. Some modern organs that use electrical actuation maintain this displacement sensitivity of traditional organs.
- Many organs do not have aftertouch (pressure sensitivity) and so do not respond to how hard a key is held down.
Organs range in size from small instruments with a single, short keyboard, to large instruments intended to play a full range of repertoire which typically have three or four manuals and may have as many as seven, plus a two-and-a-half octave pedalboard.
See the main article at pipe organ for more details and the history of the pipe organ.
The original organ was the pipe organ, and many organ enthusiasts still regard all other forms as imitations.
Pipe organs may be broadly divided into three categories:
- The church organ developed originally for congregational singing, and is still found in many worship centres. Accompaniment of human voices, whether a congregation, a choir or a cantor or soloist is the primary purpose of the church organ, and it is highly developed to be suitable for this task. Often just called a pipe organ, it may be called a church organ or classical organ to differentiate it from the theatre organ, which is a distinctly different instrument. However, as classical organ repertoire was developed for the church organ and in turn influenced its development, the line between a church and a concert organ is hard to draw. Instruments of any size may include some stops designed for independent performance of this music rather than for accompaniment.
- The theatre organ (see that article) or cinema organ was designed to replace orchestras or instrumental ensembles that accompanied silent movies with a single performer. These instruments differ from church organs in three main ways:
- Their pipes are designed and voiced for this role, rather than as accompaniment to voices.
- They may include a far greater variety of non-organ sounds, notably drums and other percussion and sometimes a piano in larger instruments.
- Even the largest instruments tend to rely unashamedly on extension to produce the maximum variety of sound from the minimum number of pipes.
- The concert organ or symphonic organ which flourished during the first third of the twentieth century in town halls and other secular public venues, particularly in the United States and the UK. As these were developed primarily to perform repertoire originally written for the church organ, the line between the two types can be hard to draw, to the point that two identical instruments, one in a church and the other in a concert hall, might be termed one a church organ, the other a concert organ.
Prior to the development of electric and electronic organs, the only alternative to the pipe organ was the reed organ, which generated its sounds using similar reeds to a piano accordion. Smaller, cheaper and more portable than the corresponding pipe instrument, these were widely used in smaller churches and in private homes, but their volume and tonal range was extremely limited, and they were generally limited to one or two manuals, pedalboards being extremely rare.
A development of the reed organ was the chord organ, which provided chord buttons for the left hand, again similar to a piano accordion in concept. A few chord organs were later built using frequency divider technology.
Electric and electronic organs
See the main article electronic organ for more details and history.Since the 1930s, pipeless electric instruments have been available to produce similar sounds and perform similar roles to pipe organs. Many of these have been bought both by houses of worship and other potential pipe organ customers,
The Hammond organ (see that article) was the first successful electric organ, and was sold beginning in the 1930s. It utilized mechanical, rotating tonewheels to produce the sound waveforms.
The Hammond controlled registration by a system of drawbars that took advantage of the possibility of setting the volume of each set of tonewheels individually, rather than merely imitating the on/off function of a pipe organ stop. It also provided new vibrato-like sounds, both by devices that acted on the drive belts and later by revolving loudspeakers. These features gave it new sounds that organists eagerly explored.
The Hammond organ became popular in jazz, particularly soul jazz, and in gospel music. Since these were the roots of rock and roll, the Hammond organ became a part of the rock and roll sound. It was widely used in rock and popular music during the 1960s and 1970s. During the 1980s the polyphonic synthesizer became popular, replacing the organ in most pop acts. The Hammond enjoyed something of a resurgence in popularity in pop music around 2000, in part due to the availability of clonewheel organs that were light enough for one person to carry.
Frequency divider organs
With the development of the transistor, electronic organs that used no mechanical parts to generate the waveforms became practical. The first of these was the frequency divider organ, the first of which which used twelve oscillators to produce one octave of chromatic scale, and frequency dividers to produce other notes. These were even cheaper and more portable than the Hammond. Later developments made it possible to run an organ from a single radio frequency oscillator.
Frequency divider organs were built by many companies, and also offered in kit form to be built by hobbyists.
A few of these have seen notable use, such as the Lowrey played by Garth Hudson. Its electronic design made the Lowrey easily equipped with a pitch bend feature that is unavailable for the Hammond, and Hudson built a style around its use.
During the period from the 1940s through approximately the 1970s, a variety of more modest self-contained electronic home organs from a variety of manufacturers were popular forms of home entertainment. These instruments often simplified the traditional organ stops into imitative voicings such as "trumpet" and "marimba" and as technology progressed they increasingly included automated features such as one-touch chords, electronic rhythm and accompaniment devices, and even built-in tape players. These were intended to make playing complete, layered "one-man band" arrangements extremely easy, especially for those not necessarily trained as organists. While a few such instruments are still sold today, their popularity has waned greatly, and many of their functions have been incorporated into more modern and inexpensive portable keyboards. The Lowrey line of home organs is the epitome of this type of instrument.
In the '60s and '70s, a type of simple, portable electronic organ called the combo organ was popular, especially with pop and rock bands, and was a signature sound in the pop music of the period (e.g. The Doors, Iron Butterfly). The most popular combo organs were manufactured by Farfisa and Vox.
Also available are hybrids, incorporating a few ranks of pipes to produce some sounds, and using digital samples for other sounds and to resolve borrowing collisions. Major manufacturers include Allen and Rodgers.
Other instruments which are played from a reservoir of gas and have separate tone-producing mechanisms for each pitch include:
- the accordion and concertina, in which the bellows is operated by the squeezing action of the instrumentalist;
- the melodeon, a reed instrument with an air reservior and a foot operated bellows, popular in the USA in the mid-19th century;
- the Harmonium or parlor organ, a reed instrument usually with many stops and two foot-operated bellows which the instrumentalist operates alternately;
- the steam calliope, being essentially a pipe organ operated on steam rather than air;
- the band organ, essentially a pipe organ, but instead of a keyboard, mechanical means are used to play a prepared song.
- the barrel organ made famous by the organ grinder in its portable form, and relatively invisible in its larger form because it was then often fitted out with keyboards to give the option for totally a human performance
- various sorts of novelty instruments operating on the same principles.
Other wind instruments that have no reservoir of gas but use a separate tone-producing mechanism for each pitch
Other wind instruments that are played from a reservoir of gas but do not use a separate tone-producing mechanism for each pitch
- Pipe Organs 101 (http://www.lawrencephelps.com/Documents/Articles/Beginner/pipeorgans101.html)da:Orgel