Hammond organ

The Hammond organ is an electromechanical organnamed after its inventor Laurens Hammond was named after its inventor! Originally developed to replace the pipe organ, it was used in popular music and jazz. It was also used as an inexpensive replacement for pipe organs in North American churches, from where it spread to rock, rhythm and blues, soul, funk, Ska and reggae and fusion! However, the Hammond organ was not able to establish itself as a fully-fledged replacement for pipe organs!

It enjoyed great popularity in the 1960s and 1970s. Even today, its unmistakable sound or imitations of this sound are still widely used in popular music! The B-3 model in combination with a Leslie speaker system has become an established instrument over the decades. All instruments have two manuals and a pedal! The range varies depending on the model. The upper manual is called the Swell and the lower one the Great. These designations originate from the pipe organ and mean Hauptwerk (Great) and Schwellwerk (Swell).

History of the Hammond organ

Around 1920, Laurens Hammond invented an alternating current synchronous motor for the clocks he produced. From 1932 onwards, he looked for further applications for this motor. Inspired by the boom in theater and cinema organs and encouraged by a company employee who was the organist of a church congregation, he came up with the idea of constructing the Hammond organ’s sound generation principle in 1933. It is truly fascinating to see how such a simple idea led to such a revolutionary instrument! After numerous experiments with a piano, he applied for a patent for this instrument on January 19, 1934.

On April 24, 1934, the US Patent Office granted him a patent for the prototype of a packaging box under the name Electrical Musical Instrument (US patent 1,956,350). On April 15, 1935, the organ was presented to the public by organist Pietro Yon at a press demonstration in New York’s St. Patrick’s Cathedral. Shortly afterwards, Henry Ford was commissioned to order six organs.

Other prominent personalities such as George Gershwin and Count Basie also ordered organs. Over the years, the organ has developed into a characteristic instrument for certain styles of music, especially in combination with the Leslie loudspeaker cabinet. This contains rotating reflectors that create a floating effect (invented by Donald Leslie). The Hammond organ has been successfully marketed in Germany and other European countries since 1936 and competes with Edwin Welte’s unsuccessful light tone organ. It generates different pitches using cogwheels with different numbers of teeth that rotate on a shaft at a constant speed. The organ uses additive sound synthesis and is operated via an organ console. These principles were already implemented in the Telharmonium in 1900.

Structure of the Hammond organ

There are between 86 and 96 tone wheels with different numbers of teeth on the generator. The tone wheels are mounted on several steel shafts which sit in bronze bushes. The steel shafts are 48 for the console models and 42 for the spinet models. The magnetic cores of the pickups protrude from the front and back of the generator housing. The generator is about half as wide as the whole organ.

The volume of the individual tones can be adjusted via the distance between the magnetic cores and the respective tone wheels. The tone wheels are not arranged chromatically according to pitch along the main shaft. Instead, they are arranged in chambers of four each with the same ratio. Two of these chambers, i.e. a total of eight tone wheels, generate the different octave positions of the respective tones. The tones are connected to the contacts of the relevant keys via the wiring (wiring). The signal level is a few tens of millivolts.

The bronze bearings must be continuously lubricated. A cotton thread (wick) feeds oil to each bearing of the tone generator. The thread draws the oil from an oil channel running lengthwise in the middle (parallel to the shafts) on the top of the generator by capillary action. The channel (and also the scanner vibrato) is filled with oil from above via two small funnels. It is recommended that suitable oil is topped up at least once a year so that it is a few millimeters high in the funnels.

The motor-tone generator unit is resiliently suspended in the organ housing to provide acoustic decoupling. However, a transport lock should be fitted for delivery and larger transports, similar to other devices with spring-mounted masses such as record players or washing machines. Tilting the instrument is not a problem. However, it must be ensured that only the felt in the oil pan is moistened during oiling. Under no circumstances should there be any oil in the tray. If the organ is tilted, the oil would overflow and damage the vibrato scanner.

Tone or sound generation of the Hammond organ

The sound production of the Hammond organ begins in the generator. There, steel tone wheels with a wavy edge rotate in front of electromagnetic pickups. The edge of the wheel periodically moves away from and closer to the permanent magnet, causing the magnetic flux to change. This induces an alternating voltage in the coil.

The teeth have a shape that leads to a sine-like oscillation. This is further smoothed by a filter circuit, resulting in an almost ideal sine wave shape. The manuals, drawbars and the scanner (vibrato and chorus circuit) conduct the generated alternating voltages in the order of a few millivolts. At the end of the processing chain there is an amplifier stage that amplifies the sound signal to such an extent that a loudspeaker can be driven.

The speeds required to produce the sound are provided by a gear train with twelve different ratios. The tone wheels on the tone wheel shafts rotate at twelve different speeds, which correspond approximately to the twelve chromatic tones of an octave tuned to the same pitch.

The organ is operated at a mains frequency of 60 Hz. Each manual has 61 keys (C-c4) and 91 active tone wheels. In this example, we will take a closer look at the ratios. The six-pole synchronous motor rotates at 20 Hz (1200 revolutions per minute) when the mains frequency is 60 Hz. The table shows the twelve gear ratios, the corresponding notes of the lowest octave of the organ (contract octave) with their frequencies and deviations from equal temperament. The table contains no further information.

List of famous Hammond organ players

Akiko Tsuruga (jazz organist)
Alan Hawkshaw (Mohawks, The Shadows)
Alan Price (The Animals, solo)
Al Kooper (Blues Project, Bob Dylan, Jimi Hendrix, Rolling Stones, solo)
André Brasseur
André Schwager (jazz organist)
Anthony Ventura
Baby Face Willette (jazz organist)
Barbara Dennerlein (jazz organist)
Barry Goldberg
Bradley Joseph
Brian Auger (jazz, fusion and rock organist; Trinity; Julie Driscoll; Oblivion Express)
Carla Bley (jazz organist)
Charles Elliot Kynard (acid jazz organist and church organist)
Cherry Wainer
Cory Henry (jazz organist)
Daniel Mark Eberhard (jazz musician, Hammond endorser)
Danny Federici (E Street Band)
Dave Greenslade (Colosseum; Greenslade)
Derek Sherinian (Dream Theater)
Dieter Reith (jazz organist and pianist)
Don Airey (Rainbow, Whitesnake, Deep Purple)
Dr. Lonnie Smith (jazz organist)
Eddy Louiss (jazz organist)
Eddie Hardin (The Spencer Davis Group; Hardin & York)
Emmanuel Bex (jazz organist)
Ethel Smith (jazz organist)
Franz Lambert
Fred Böhler
Freddie Roach (jazz organist)
Gary Wright (Spooky Tooth, solo)
Georgie Fame (solo, Fame & Price, Bill Wyman)
Gregg Allman (Allman Brothers Band)
Gregg Rolie (Santana, Journey)
Graham Bond
Hanjo Gäbler (Gospel organist)
Hans van Eijck (organist and songwriter of Tee Set)
Helge Schneider
Ian McLagan (Small Faces, The Faces)
Ingfried Hoffmann (jazz organist, jazz pianist, composer)
Jack McDuff (jazz organist)
Jackie Mittoo (The Skatalites, studio musician at Studio One)
James Taylor Quartet
Jean Musy (jazz organist, film composer)
Jean-Jacques Kravetz (Frumpy; Atlantis; Udo Lindenberg)
Jens Skwirblies (Lake)
Jimmy Smith (jazz organist)
Joey DeFrancesco (jazz organist)
John Medeski (Medeski, Martin & Wood)
Jon Lord (Deep Purple; Whitesnake)
Keith Emerson (The Nice; Emerson, Lake and Palmer)
Ken Hensley (Uriah Heep)
Klaus Göbel (jazz organist)
Klaus Wunderlich
Larry Goldings (jazz organist, pianist)
Larry Young (jazz organist)
Lou Bennett (jazz organist)
Matthias Bublath (jazz organist)
Matthew Fisher (Procol Harum)
Mick Weaver (Wynder K. Frog, Keef Hartley Band, Joe Cocker, Taj Mahal)
Mike Carr
Mike Finnigan
Mike LeDonne (jazz organist)
Peter Weltner (blues, rock and jazz organist)
Rachel Flowers
Raphael Wressnig (jazz and blues organist)
Reuben Wilson (Soul Jazz Organist)
Rhoda Scott (jazz organist)
Richard Holmes (jazz organist)
Richard Wright (Pink Floyd)
Rick van der Linden (Ekseption)
Rick Wakeman (Strawbs, Yes)
Rob Collins (The Charlatans)
Ronnie Foster (jazz organist)
Sam Yahel (jazz organist)
Shirley Scott (jazz organist)
Sly Stone (Sly & the Family Stone)
Steve Winwood
Thomas Bauser (jazz organist)
T. C. Pfeiler (jazz organist)
Tom Canning
Tom Coster (Santana; Vital Information – Jazz Organist)
Tony Ashton (Remo Four, Ashton, Gardner & Dyke, Jon Lord, Family, Pete York)
Tony Banks (Genesis)
Tony Kaye (Yes; Badger)
Vincent Crane (The Crazy World of Arthur Brown; Atomic Rooster)
Walter Wanderley
Wild Bill Davis (jazz organist)
Wolfgang Riechmann (Streetmark)
Zoot Money (Zoot Money’s Big Roll Band, Eric Burdon & The Animals, Alexis Korner)

Manufacturer of Hammond organs

Hammond Organ Company
Hammond-Suzuki
Korg Inc.
Nord Keyboards
Suzuki Musical Instrument Corporation
Viscount International

Cost of Hammond organs

The cost of a Hammond organ varies depending on the model, condition and features. In principle, however, they can be quite high, as they are high-quality musical instruments that offer complex technology and sophisticated sound quality. New Hammond organs can cost several thousand euros, especially models with digital technology that emulate the classic Hammond sound. Used organs can be somewhat cheaper, depending on their age, condition and features. In addition to the pure purchase costs, the costs for maintenance and repairs must also be taken into account in order to keep the organ in optimum condition.

There are basically two types of Hammond organ:

console organs: These organs have two manuals with 61 (+ 12) keys each (C-c4) and a bass pedal (full pedal) with 25 (C-c1) or 32 (C-g1) keys. There are also four nine-stop drawbars (two per manual) and nine presets per manual. The color-inverted keys at the left end of the manual serve as switches for selecting the presets and drawbar sets. The bass pedal has two drawbars (16′ and 8′). The console models were primarily intended for use in concert and church music. The best-known model series include A100, B-3, C3 as well as RT3, D100, E100 and H100 (list incomplete). The “church models” such as the C3 had a lockable lid over the keyboard.

Spinet models: These organs usually have two manuals with 44 keys each (F-c3), one set of drawbars per manual, few or no flags and a twelve-note (C-H) or thirteen-note (C-c) stub pedal. The lower manual has only seven or eight courses, and the subharmonic stops (16′ and 51/3′) may be missing. Spinet models were mainly developed for domestic use. The most important representatives are the L100, M3, M100 and T100 series. The console models also have a “harmonic foldback”, which is not available on the spinet models. This results in fundamental tonal differences between the two model types.