The

Hammond organ The Hammond organ is an electric organ invented by Laurens Hammond and John M. Hanert and first manufactured in 1935. Multiple models have been produced, most of which use sliding drawbars to vary sounds. Until 1975, Hammond organs generated s ...

is an

electric organ An electric organ, also known as electronic organ, is an electronic keyboard instrument which was derived from the harmonium, pipe organ and theatre organ. Originally designed to imitate their sound, or orchestral sounds, it has since developed ...

, invented by

Laurens Hammond Laurens Hammond (January 11, 1895 – July 1, 1973), was an American engineer and inventor. His inventions include the Hammond organ, the Hammond clock, and the world's first polyphonic musical synthesizer, the Novachord. Youth Laurens ...

and John M. Hanert and first manufactured in 1935. Various models were produced, which originally used

tonewheel A tonewheel or tone wheel is a simple electromechanical apparatus used for generating electric musical notes in electromechanical organ instruments such as the Hammond Organ and in telephony to generate audible signals such as Ringing tone. It ...

s to generate sound via

additive synthesis Additive synthesis is a sound synthesis technique that creates timbre by adding sine waves together. The timbre of musical instruments can be considered in the light of Fourier series, Fourier theory to consist of multiple harmonic or inharmoni ...

, where component waveform ratios are mixed by sliding switches called

drawbars The Hammond organ is an electric organ invented by Laurens Hammond and John M. Hanert and first manufactured in 1935. Multiple models have been produced, most of which use sliding drawbars to vary sounds. Until 1975, Hammond organs generated ...

and imitate the pipe organ's registers. Around 2 million Hammond organs have been manufactured, and it has been described as one of the most successful organs ever. The organ is commonly used with, and associated with, the

Leslie Speaker The Leslie speaker is a combined amplifier and loudspeaker that projects the signal from an electric or electronic instrument and modifies the sound by rotating a baffle chamber ("drum") in front of the loudspeakers. A similar effect is provided ...

Tonewheel organs

Tonewheel organs generate sound by shaped mechanical wheels, that rotate in front of electromagnetic pickups. Each tonewheel assembly creates tones with low harmonic content, close to a sine wave. Inside the coil is a permanent magnet. As the profile of the tonewheel pass by, the strength of the magnetism changes—when the highest part is closest to the tip of the magnet, the magnetism is strongest. As the magnetism varies, that induces an alternating current (AC) in the coil, which becomes one of the frequencies used in harmonic synthesis. Two models in Church-styled cabinet were made under military specifications, and named G (G for "Government contract", with chorus), and G-2 (with vibrato), to be installed in chapels and officer's messes of U.S. Army and Navy.

Vacuum tube musical instruments

Vacuum tube musical instruments mean

electronic musical instruments Electronic may refer to: *Electronics, the science of how to control electric energy in semiconductor * ''Electronics'' (magazine), a defunct American trade journal *Electronic storage, the storage of data using an electronic device *Electronic co ...

generating sound with

vacuum tube A vacuum tube, electron tube, valve (British usage), or tube (North America), is a device that controls electric current flow in a high vacuum between electrodes to which an electric voltage, potential difference has been applied. The type kn ...

-based

electronic oscillator An electronic oscillator is an electronic circuit that produces a periodic, oscillation, oscillating electronic signal, often a sine wave or a square wave or a triangle wave. Oscillation, Oscillators convert direct current (DC) from a power supp ...

s. Hammond Organ Company commercialized it in the late-1930s as

Novachord The Novachord is an electronic musical instrument often considered the world's first commercial polyphonic synthesizer. All-electronic, incorporating many circuit and control elements found in modern synthesizers, and using subtractive synthesi ...

(1939–1942) and Solovox (1940–1948). Especially, new designs introduced on Novachord —

subtractive synthesis Subtractive synthesis is a method of sound synthesis in which partials of an audio signal (often one rich in harmonics) are attenuated by a filter to alter the timbre of the sound. While subtractive synthesis can be applied to any source audio si ...

and

frequency divider A frequency divider, also called a clock divider or scaler or prescaler, is a circuit that takes an input signal of a frequency, f_, and generates an output signal of a frequency: : f_ = \frac where n is an integer. Phase-locked loop frequency ...

— were immediately followed by many manufacturers of

electronic organ An electric organ, also known as electronic organ, is an electronic keyboard instrument which was derived from the harmonium, pipe organ and theatre organ. Originally designed to imitate their sound, or orchestral sounds, it has since developed ...

s and

polyphonic synthesizer Polyphony is a property of musical instruments that means that they can play multiple independent melody lines simultaneously. Instruments featuring polyphony are said to be polyphonic. Instruments that are not capable of polyphony are monophoni ...

s during the 1940s-1970s. However, Hammond Organ Company did not adopt these on main products until the late-1960s, except for S series

chord organ Chord organ is a kind of home organ that has a single short keyboard and a set of chord buttons, enabling the musician to play a melody or lead with one hand and accompanying chords with the other, like the accordion with a set of chord button ...

(1950–1966) and "Solo Pedal Unit" on RT series and D-100 (1949–1969).

Transistor organs

Hammond started to produce transistor organs when the production of tonewheels became too expensive, switching to full-time Integrated Circuit (IC) models in 1975.

Digital organs

After the Hammond Organ Company ceased trading in 1985, production initially went to Noel Crabbe's Hammond Organ Australia, and then to

Suzuki Musical Instrument Corporation The is a Japanese company that produces a range of musical instruments. History Suzuki was founded in 1953 by Mr. Manji Suzuki. Initially the company manufactured Harmonicas and later developed the Melodion which in 1956 was officially adopted ...

, who, under the name Hammond-Suzuki, manufacture digital organs.

References

;Bibliography * * * * * * * ;Other sources * * ** (recreation of original in 1970); Originally published as: **
Note: It seems a retyped copy of original "Introductory Section" of ''Service Manual'' in circa 1975, or similar. **
Note: It seems a reprint of "Introductory Section" of ''Service Manual'' circa 1984, or similar. * {{Electronic organs Hammond Electronic organs