An electric organ, also called an electronic organ, is a keyboard instrument that came from the harmonium, pipe organ, and theatre organ. It was first made to copy the sounds of these instruments or the sounds of an orchestra. Over time, it has now become many different kinds of instruments.

History

The earlier version of the electronic organ was the harmonium, also called the reed organ. This instrument was often found in homes and small churches during the late 1800s and early 1900s. Like pipe organs, reed organs create sound by forcing air over reeds using a bellows, which is usually operated by pumping pedals. The harmonium used pressure, while the American reed organ used suction. Although reed organs have limited sound quality, they are small, inexpensive, self-powered, and easy to move. Larger models had multiple manuals or pedal boards, with the bellows operated by a lever or crank, or in some cases, an electric pump. These features allowed reed organs to provide an organ-like sound in places that could not support or afford pipe organs. This idea helped lead to the creation of the electric organ.

In the 1930s, several companies made electronic organs that tried to copy the sound and function of pipe organs. Some believed that copying pipe organs was the best way to develop electronic organs, but others disagreed. Over the years, many types of electronic organs were made, each finding success in their own areas.

Electricity was first used in organs in the early 1900s, but it took time to make a big difference. Electric reed organs appeared during this time, but their sound quality was similar to older, foot-pumped models.

Thaddeus Cahill created a large and controversial instrument called the Telharmonium in 1897. It sent music through telephone lines to businesses in New York City. Though it came before modern electronics, it was the first instrument to use electrical waveforms to create sounds like real instruments. Cahill’s methods later influenced Laurens Hammond, who used them in his organ designs. The Telharmonium was the first large-scale example of music made electronically.

At the same time, experiments with electric impulses to create sound were happening, especially in France.

After the Telharmonium failed, similar designs called tonewheel organs were developed. Examples include:

• Robb Wave Organ by Morse Robb (Canada) — created around 1923, sold from 1936–1941
• Rangertone by Richard Ranger (United States) — sold around 1932
• Hammond organ by Laurens Hammond and John M. Hanert (United States) — invented in 1934, sold from 1935–1975
• Lichtton Orgel by Edwin Welte, et al. (Germany) — an optical-tonewheel sampling organ, sold from 1935–1940s

One of the earliest electric tonewheel organs was made by Morse Robb of the Robb Wave Organ Company in Belleville, Ontario. Though it was created before the more successful Hammond organ, the company closed in 1938 due to lack of money.

The first major success in this field came from the Hammond Clock Company in 1934. The Hammond organ quickly replaced the reed organ, becoming the most popular option.

Tonewheel organs worked differently from earlier organs. Instead of reeds or pipes, Robb and Hammond used spinning magnetic wheels called tonewheels. These wheels created electrical signals that were mixed, amplified, and sent to a loudspeaker. The organ was powered by electricity, replacing the reed organ’s bellows pedals with a single swell pedal, similar to a pipe organ. This allowed the organist to control volume easily, freeing their feet to play a pedalboard, which most reed organs did not have. Electronic organs also had a second manual, something rare in reed organs. These features required more skill from the organist but greatly improved the instrument’s capabilities.

The most important difference in the Hammond organ was its many tonewheel settings, controlled by drawbars near the manuals. Using these drawbars, the organist could mix different electrical tones and harmonics in various ways, creating over 250 million possible sounds. Combined with its three-keyboard layout, electrical power, and wide volume control, the Hammond organ was more flexible than any reed organ or most other instruments except the pipe organ.

The classic Hammond sound is enhanced by loudspeakers called tone cabinets. These are often paired with rotating speaker units made by Leslie.

The Hammond Organ became popular in many music genres, including jazz, gospel, pop, and rock. Bands like Emerson, Lake, and Palmer, Booker T. & the M.G.'s, and Deep Purple used it. Sometimes, the legs of these instruments were removed to make them easier to transport. The most famous Hammond model is the B3. Though portable "clonewheel" organs began replacing the original design in the 1970s, the Hammond is still widely used by professional organists. Refurbished Hammond instruments remain in demand, even as newer technology allows modern organs to perform at higher levels.

After the Hammond organ was invented in 1934, other companies explored different electric or electronic organ designs. One idea was a purely electronic version of the pipe organ using "additive synthesis," but this required many oscillators, which were difficult to build with the technology of the time. Benjamin Miessner suggested a hybrid design that combined acoustic tone generators with electronic circuits.

The Orgatron was created in 1934 by Frederick Albert Hoschke, based on a Miessner patent. It used a fan to blow air over free reeds, which vibrated and were picked up by capacitive sensors. The electrical signals were then processed and amplified to create music. The Orgatron was made by the Everett Piano Company from 1935 to 1941. Production continued after World War II by the Rudolph Wurlitzer Company until the early 1960s.

In 1955, the German company Hohner released two electrostatic reed organs: the Hohnerola and the Minetta, invented by Ernst Zacharias.

At the same time, similar electro-acoustic instruments, such as electric-fan-driven free reeds, were being developed.

In churches

In the 1930s, early combinations of pipe organs and electronic technology, such as electronic sound makers, were developed. Sometimes, custom electronic organ consoles are used to replace older pipe consoles. These updates improve the electrical control system for the pipes and add new electronic sounds to the organ. Even large pipe organs often include electronic sounds to produce very deep bass tones that would otherwise require very long pipes, such as 16- to 32-foot pipes.

Hybrid organs, which mix pipes and electronic sounds, have pipes that change pitch based on environmental conditions, but electronic sounds do not change automatically. The pitch of a pipe depends on its shape and the speed of sound inside it. These factors can shift slightly with changes in temperature and humidity, causing the pipe’s pitch to vary slightly. The electronic part of a hybrid instrument must be adjusted regularly. This can be done manually by the organist or automatically in newer models.

The first complete electronic church organ was created in 1939 by Jerome Markowitz, who later founded the Allen Organ Company. He worked for many years to create realistic pipe organ sounds using circuits based on radio tubes. In 1958, the Rodgers Organ Company built the first church organ using solid-state, transistor-based technology, called the Opus 1.

Unlike systems that use only a few independent pitch sources, high-quality electronic church organs have at least one oscillator for each note and often additional sets to create a richer sound. For example, the Rodgers Opus 1 had eight sets of transistor-based pitch generators. Today, digital organs use software-based digital oscillators to produce many independent pitch and tone sources, better mimicking the sound of a large pipe organ.

Digital church organs are designed to replace pipe organs or to control existing pipes. Differences in sound quality between pipe and digital instruments are debated, but digital organs are usually less expensive and take up less space.

Digital organs are a practical choice for churches that can no longer afford to maintain a pipe organ. Some pipe organs, however, can remain playable for many years without major repairs. Pipe organs are expensive to build and take longer to design, build, and "voice," which has limited their production.

Most modern digital church organs use recorded samples of pipe sounds, though some use a method called additive synthesis to model pipe sounds. This process is done by a professional organ "voicer," who finishes the organ in its location, similar to how pipe organs are regulated and voiced. These organs also use high-quality audio systems. Companies that build custom and factory-made digital church organs include Ahlborn-Galanti, Allen, Eminent, Johannus, Makin, Rodgers, Viscount, and Wyvern.