ELECTRONIC ORGAN

An 'electronic organ' is an electronic keyboard instrument originally designed to imitate the sound of a pipe organ. It has developed today into two forms of the instrument, the imitation pipe organ as used in churches, and the Hammond organ-style instrument used in more popular music genres.

Pipeless classical instruments

2006 Rembrandt Digital organ - an example of a large pipeless organ that could be used in a church.

The high-quality instruments designed purely as pipe organ replacements, have developed greatly over the last two decades, and are now a common alternative to the pipe organ, particularly in churches. These are often referred to as 'pipeless' or 'digital organs'. The technology has advanced to such a level that there is very little difference in sound timbre between piped and pipeless instruments, although this is still keenly debated between organists, who still agree that there is no true substitute for a ''real'' pipe organ. However, many churches that are unable to afford costly pipe organs have turned to less-expensive electronic organs as a viable alternative; even a congregation that could afford a modest pipe organ may instead opt for a digital organ that simulates a much larger pipe organ than they could afford. Digital Organs by custom builders have also become a viable alternative for churches who may have had a pipe organ and can no longer afford to maintain it, or for those situations where a pipe organ is not financially possible.
Most of the digital organs produce sounds by playing back recorded samples, while others use computers to actually model the pipe sound in real time. Digital organs offer a significant cost savings as with today's systems, little or no maintenance may ever be required, as the cost of maintaining pipe organs is very expensive. That isn't to say that the top-of-the-range digital organs are not expensive. Custom Real Time Systems will require special computer systems and usually require an experienced trained organist to finish or "voice" the organ, much like the process of regulating and voicing any pipe organ. These organs typically use very high quality custom designed audio systems. A high end Custom Sampled Technology organ may require over 40 hours worth of stored sampled sound as well as using some of the same audio concepts as the real time builders. the builders of both custom and factory organs include the firms of Allen and Rodgers.
This style of instrument is also popular with popular concert organists, such as Carlo Curley, who tours with a substantial Allen Organ, which means he does not need to spend time getting used to a new pipe organ for every concert he performs. These instruments will often contain effects that are not seen on pipe organs, and there may be additional ''features'', such as percussion sounds, and console aids. The most advanced digital organs also offer some capabilities not found in pipe
organs, such as changing historical pitch standards and temperaments.

History

The immediate predecessor of the electronic organ was the harmonium, or reed organ, an instrument that was very popular in homes and small churches in the late nineteenth and early twentieth centuries. In a fashion not totally unlike that of pipe organs, reed organs generated sound by forcing air over a set of reeds by means of a bellows, usually operated by constantly pumping a set of pedals. While reed organs had limited tonal quality, they were small, inexpensive, self-powered, and self-contained. The reed organ was thus able to bring an organlike sound to venues that were incapable of housing or affording pipe organs. This concept was to play an important role in the development of the electric organ.
Electricity arrived on the organ scene in the first decades of the 1900s, but it was slow to have a major impact. Thaddeus Cahill's gargantuan and controversial instrument, the Telharmonium, which began piping music to New York City establishments over the telephone system in 1897, predated the advent of electronics, yet was the first instrument to demonstrate the use of the combination of many different pure electrical waveforms to synthesize real-world instrument sounds. Cahill's techniques were later used by Laurens Hammond in his organ design, and the 200-ton instrument served as the world's first demonstration of electrically-produced music on a grand scale. Electrically powered reed organs appeared during the first decades of electricity, but their tonal qualities remained much the same as the older, foot-pumped models. Meanwhile, some further experimentation with producing sound by electric impulses was taking place, especially in France. The first widespread success in this field, however, was a product of the Hammond Corporation in the mid-1930s. The Hammond Organ quickly became the successor of the reed organ, displacing it completely.
From the start, electronic organs operated on a radically different principle from all previous organs. In the place of reeds and pipes, Hammond introduced a set of rapidly spinning magnetic wheels, called tonewheels, which excited transducers that generated electrical signals of various frequencies that were mixed and fed through an amplifier to a loudspeaker. The organ was electrically powered, replacing the reed organ’s twin bellows pedals with a single swell (or "expression") pedal more like that of a pipe organ. Instead of having to pump at a constant rate, as had been the case with the reed organ, the organist simply varied pressure on this pedal at will to change the volume as desired. Unlike reed organs, this gave great control over the music's dynamic range, while at the same time freeing one or both of the player's feet to play on a pedalboard, which, unlike nearly all reed organs, electronic organs incorporated. From the beginning, the electronic organ also had a second manual, also very rare among reed organs. While this meant that the electronic organ required greater musical skills of the organist than the reed organ had, the second manual and the pedalboard along with the expression pedal greatly enhanced playing, far surpassing the reed organ's limited capabilities.
The most revolutionary difference in the Hammond, however, was its huge number of tonewheel settings, achieved by manipulating a system of drawbars located near the manuals. By using the drawbars, the organist could combine a variety of electrical tones and harmonics in varying proportions, thus giving the Hammond vast "registration." In all, the Hammond was capable of producing more than 250 million tones. This feature, combined with the three-keyboard layout (i.e., manuals and pedalboard), the freedom of electrical power, and a wide, easily controllable range of volume made the first electronic organs far more flexible than any reed organ, or indeed any other musical instrument in history except, perhaps, for the pipe organ itself.
In the wake of the Hammond Organ’s invention, later models—especially those of competitors—used various combinations of oscillators and filters to produce electric tones. Today, however, modern electronic organs use high-quality digital samples to produce as accurate a sound as possible. The heat generated by early models with vacuum tube tone generators and/or amplifiers led to the somewhat derogatory nickname "toaster"; today’s solid-state instruments do not suffer from this problem nor do they require the several minutes the the vacuum tube organs needed to bring the filament heaters up to temperature.
Electronic organs were once popular home instruments, comparable in price to pianos and frequently sold in department stores. After their début in the 1930s, they captured the public imagination, largely through the film performances of Hammond organist Ethel Smith. Nevertheless, they initially suffered in sales during the Great Depression and World War II. After the war they became more widespread, peaking in popularity in the 1950s and early 1960s, but undoubtedly undercut by the rapid growth of television and high fidelity audio systems as home entertainment alternatives during that same period. Home electronic organ models usually attempted to imitate the sounds of theatre organs and/or Hammonds, rather than classical organs.

The spinet organ

Following World War II, most electronic home organs were built in a configuration usually called a spinet organ, which first appeared in 1949. These compact and relatively inexpensive instruments became the natural successors to the reed organs. They were marketed as competitors of home pianos and often aimed at would-be home organists who were already pianists (hence the name "spinet," a small upright piano). The instrument's design reflected this concept: the spinet organ physically resembled a piano, and it presented simplified controls and functions that were both less expensive to produce and less intimidating to learn. One feature of the spinet was automatic chord generation; with many models, the organist could produce an entire chord to accompany the melody merely by playing the tonic note, i.e., a single key, on a special section of the manual.

A typical spinet organ of the 1950’s. Note the resemblance in size and shape to a small home piano. Note also the shortened, offset manuals and miniature pedalboard, both sure signs of the spinet.

On spinet organs the keyboards were typically at least an octave shorter than is normal for organs, with the upper manual missing the bass, and the lower manual missing the treble. The manuals were usually offset, inviting (although not requiring) the new organist to dedicate the right hand to the upper manual and the left to the lower, rather than using both hands on a single manual. This seemed designed in part to encourage the pianist, who was accustomed to a single keyboard, to make use of both manuals. Stops on such instruments, relatively limited in number, were frequently named after orchestral instruments that they could, at best, only roughly approximate, and were often brightly colored (even more so than those of theatre organs). The spinet organ's loudspeaker, unlike the original Hammond models of the 1930s and 1940s, was housed within the main instrument (behind the kickboard), which saved even more space, although it produced a sound inferior to that of free-standing speakers.
The spinet organ’s pedalboard normally spanned only a single octave, was often incapable of playing more than one note at a time, and was effectively playable only with the left foot (and on some models only with the left toes). This limitation, combined with the shortened manuals, made the spinet organ all but useless for performing or practicing classical organ music, but at the same time it allowed the novice home organist to explore the challenge and flexibility of simultaneously playing three keyboards (two hands and one foot). The expression pedal was located to the right and either partly or fully recessed within the kickboard, thus conveniently reachable only with the right foot. This arrangement spawned a style of casual organist who would naturally rest the right foot on the expression pedal the entire time, unlike classically-trained organists or performers on the earlier Hammonds. This position, in turn, instinctively encouraged pumping of the pedal while playing, especially if already accustomed to using a piano’s sustain pedal to shape the music. Expressive pumping added a strong dynamic element to home organ music that much classical literature and hymnody lacked, and would help influence a new generation of popular keyboard artists.

The chord organ

Shortly after the debut of the spinet the "chord organ" appeared. This was an even simpler instrument designed for those who wanted to produce an organlike sound in the home without having to learn much organ (or even piano) playing technique. The chord organ had only a single manual that was usually an octave shorter than its already-abbreviated spinet counterpart. It relied more heavily on automatic chord generation than other models; it also possessed scaled-down registration and no pedalboard or expression pedal (volume being determined by a knob near the manual instead, an inefficient arrangement that effectively eliminated the dynamic playing that an expression pedal allowed). The left hand operated not a keyboard but an array of chord buttons adapted from those of an accordion. Early models had two pedals sounding the root and fifth of the selected chord; later models incorporated a drum machine and auto-accompaniment unit. As was the case with the spinet, the loudspeaker was housed within the kickboard.

A typical console organ of the early 1960s. Considerably larger and more imposing than the spinet, it resembles the console of a pipe organ (yet this advertisement makes a point of emphasizing that even children are capable of mastering it, as the girl here is demonstrating). Note the five-octave in-line manuals, the extra drawbars, and the full pedalboard, all of which make this a more complex, but also a more powerful and flexible, instrument than the spinet.

The console organ

On the other end of the spectrum were larger and more expensive home models, known as “console organs” because they resembled pipe organ consoles. These instruments had a more traditional configuration, including full-range manuals, a wider variety of stops, and a two-octave (or occasionally even a full thirty-two note) pedalboard easily playable by both feet in standard toe-and-heel fashion. (Console organs having thirty-two note boards were sometimes known as "concert organs.") Console models, like spinet and chord organs, had their speakers mounted above the pedals, though the classic Hammond design of the 1930s and 1940s made use of free-standing loudspeakers, usually manufactured by Leslie, that produced a higher-quality sound than a spinet organ’s small built-in speakers. With their more traditional configuration, greater capabilities, and better performance compared to spinets, console organs were especially suitable for use in small churches, public performance, and even organ instruction. The home musician or young student who first learned to play on a console model often found that [s]he could later make the transition to a pipe organ in a church setting with relative ease.
By the 1960s, electronic organs were ubiquitous in all genres of popular music, from Lawrence Welk to acid rock and the Thin Wild Mercury Sound of the Bob Dylan album Blonde on Blonde. In some cases, Hammonds were used, while in others, very small all-electronic instruments, only slightly larger than a modern digital keyboard, called combo organs, were used. (Various organs made by Farfisa were especially popular, and remain so among retro-minded rock combos.) The 1970s 1980s and the 1990s saw increasing specialization: both the gospel and jazz scene continued to make heavy use of Hammonds, while various styles of rock began to take advantage of more and more complex electronic keyboard instruments as Large-scale integration and then digital technology began to enter the mainstream. Although the original Hammond tonewheel design was phased out in the mid-1970s, it is still very much in demand by professional organists, and the industry continues to see a lively trade in refurbished instruments even as technological advance allows new organs to perform at levels unimaginable only two or three decades ago.

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 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.

Modern technology

Modern professional electronic organs have reached a degree of sophistication, complexity, and expense surpassed only by the pipe organ itself. The consoles of some of these instruments, at first glance, may be almost indistinguishable from those of pipe organs (although a closer examination, as well as the obvious absence of pipes, will quickly reveal the difference). Electronic organs are still made for the home market, but they have been largely replaced by the digital keyboard or synthesizer, which is not only smaller and cheaper than typical electronic organs or traditional pianos, but also far more capable than the most advanced electronic organs of earlier years. Modern digital organs, by the same token, are far more advanced in design and capabilities than their ancestors.
Today’s instruments incorporate Real Time Tonal Generation, sampling, MIDI, and Internet connectivity for downloading of music data and instructional materials, as well as making use of floppy disk and media card storage. While electronically they are radically different from their predecessors, their basic appearance makes them instantly identifiable as the latest generation in a long line of electronic organs that now reaches back more than seventy years. Real Time systems are usually only found on custom digital church organs. Sample technology is also used by several custom digital builders but the difference is they used significantly longer samples than the typical digital organ.
The very best digital organs today have a number of features which distinguish their sound from that of simpler instruments, including the following.

★ Multiple digital-to-analog converters, to prevent degradation of sound quality as multiple stops are used (simpler instruments multiplex one or two DACs for all stops at once).

★ All of the organs pipe sound in todays digital organs are either derived from a computer actually producing the pipe sound in "Real Time" by generating the actual harmonics or by a sampled sound file which is recorded from an organ pipe and then processed and stored on a computer chip. Both systems are widely used in today's organs but an experienced voicer will have slightly more control of the actual harmonics on a real time system.

★ With the sampled systems, each note in each register should be sampled from that actual pipe, as opposed to simpler instruments like the early digital organs from the 80's and 90's in which one sample has its frequency shifted digitally to generate different notes.

★ Real Time systems such as Copeman & Hart, Eminent, Cantor, Van der Pole and other custom builders will use sophisticated computer hardware rather than recording sound samples.

★ With the sample technology organs like Walker Digital and Marshall & Ogletree, very long samples are used to allow a more realistic envelope, as opposed most digital organs which are required to repeat a very short sample. These systems will yield many of the same tonal and realism advantages of the real time computing systems due to the more sophisticated tonal reproduction inherent in both organs using real time system technology and organs incorporating the racks of computer systems required to store very long samples. Both of these systems will deliver a realistic pipe like quality, especially when long notes are sustained.

★ Most Sampling Systems are typically done with 24-bit or 32-bit resolution instead of CD-quality 16-bit resolution.

★ Sampling in today's organs is done at a much higher frequency than the 44,100 samples per second of CD-quality audio.

★ On most typical organs, at least four independent amplifiers are used to provide a more spacious sound. Higher quality custom digital organ builders will use custom audio and speaker systems and provide anywhere from 10 to 32 or more independent channels of audio based on the size of the organ and the overall budget of the instrument.

★ A dedicated high power sub woofer for the low frequencies of the sound; the best digital organs can thus approach the physical feeling of a real pipe organ if a sufficient number of sub woofers are used.

★ Simulated changes of windchest pressure -- when many notes are sounding at once, the air pressure of a real pipe organ will drop slightly, which changes the sound of all the pipes; some electronic organs can simulate this effect.
For hybrid organs, which combine actual pipes with electronic stops, an important issue is that pipes change pitch with the weather, but digital audio systems do not. The frequency of sound produced by an organ pipe is determined by its geometry and by the speed of sound in the air within it. The speed of sound changes with the temperature and humidity of the air; therefore the pitch of a pipe organ will change as the weather changes, so the pitch of the digital side in a hybrid instrument must be retuned as needed. The simplest way this can be done is with a manual control that the organist can adjust, but better models can make such adjustments automatically.
The processing power of today's personal computers have brought the world of organs closer than ever before. Software applications are available for Microsoft Windows and Apple Computer's Mac OS X that store digital pipe samples and sum them in real time in response to input from one or more MIDI sources. The most advanced of these is Crumhorn Labs' Hauptwerk, but others include jOrgan, SCPOP, and Miditzer. Many hobbyists have used these tools to assemble home-built organs that can rival or exceed the sound quality
of commercially built digital organs at a fraction of the cost.