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All About Jazz Organ: Inside the Hammond B-3

All About Jazz Organ: Inside the Hammond B-3

Courtesy Daniel Latorre, Robert Glabewski & Fabio Stamato


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...the Hammond organ is a way of life, a passion for an entirely different world of making music.


For most people, it's just another musical instrument, but for some, the Hammond organ can be a way of life, a passion that will lead to entirely new ways of making music. This is no ordinary organ, we are talking about an instrument that changed history and became one of the pillars in modern music. But you might ask: "What makes it so special?"

The Hammond was one of the first mass-produced musical instruments which combined the electrical, mechanical and acoustic worlds—it is a keyboard instrument that could produce totally new sounds, and at the same time "imitate" other acoustic instruments. It wouldn't be an overstatement to say it's the "grandfather of electronic music," from gospel to blues, from rock concerts to jazz clubs, the Hammond organ was truly revolutionary, serving the holy and the profane at the same time.

Back in the 1930's, during the Great Depression, Laurens Hammond, a skilled electric engineer started his venture in the electric clock business and then built his first electric organ by combining a used piano keyboard, his clock motors and his then-new invention, The Tonewheel, which creates sound through an electro-mechanical generator. From the very beginning, he had big investors interested in his work; for example, Henry Ford helped to improve the production process, allowing the Hammond Organ Company to produce organs on an unprecedented scale for a musical instrument.

The Hammond Organ Company, which was based in Chicago, manufactured organs until the mid 80's and managed to deliver thousands of units of various models. But it was in the mid 50's that the model B3 with its Leslie speaker came into being. The B3 is considered the most famous Hammond organ, especially among musicians. (The history and development of the Leslie speaker is an equally fascinating topic that deserves its own article.)

Other than being revolutionary and of great historic importance, The Hammond has always been a very powerful tool for shaping completely new sounds. This is possible by precisely combining selected harmonics to resemble acoustic instruments such as strings, winds, percussions and even highly experimental sounds. The Hammond Organ alongside Hammond's second invention, The "Hammond Novachord," are the world's first mass-produces and sold synthesizers. The invention of the Hammond organ opened the doors to analog synthesizer keyboards and later, to samplers. Over the years Hammond players developed a language of "registrations" (combination of sounds) for each style of music, with many possible variations, reinventing sounds and adding new effects to satisfy each musician's creative needs.

Today the Hammond is surrounded by an almost mythological aura. Many young musicians know the sound of a Hammond, but they don't associate that with the instrument itself. Unfortunately, for many musicians it's just another vintage organ sound, easily found in modern synthesizers and keyboard workstations. These are great and useful tools, but those who love real Hammond organs know that there is much much more.

The B3's mechanical and electronic systems are no longer manufactured, but it's still possible to get hold of a real one that will last for many more decades, as long as the instrument is carefully maintained. Restoration of old organs is also possible, largely due to the very high quality with which these old instruments were manufactured. This is sadly not the case with many modern instruments, which are not built to the same standards. Please bare in mind that finding a qualified restorer is still possible, but it's becoming more and more difficult.

The Hammond Organ Company decided to stop the tonewheel production during the mid 70's. At that time, the rising popularity of transistors and integrated circuits (IC) made the organ market much more competitive. It was possible to build electronic products faster and cheaper, which led to old technologies such as the mechanical generator and valve tubes circuits to become obsolete. The last B3 model was built in 1974, but from then until now no transistor or digital attempts to replicate the B3 have been successful. In fact, what made the B3 so special was simply the old technology and its imperfections, like the pure sine wave tone, produced by tone wheels running all the time with plenty of leaking noises and other electro-acoustic interactions, the "clicky" noises produced by the mechanical contacts, and the warmth of the tube preamplifier. What were then considered defects were later considered desirable features, but the complex, inconsistent, and unpredictable behaviors of these features are difficult to reproduce with modern circuits or digital simulation.

There are many musical instruments dedicated to reproducing the B3 nowadays. None of them can do it perfectly, but if the organ player knows how the original B3 should sound, it is possible to tweak these so-called "Hammond Clones" to achieve satisfactory results. The original Hammond organ is not yet replaceable. The feel and powerful sound of the "real deal" is still unbeatable.

Used in almost all musical genres, the Hammond Organ sound became famous in gospel, blues, soul, jazz and rock music. Today we find serious artists going deep into the world of Hammond and producing amazing music material.

Listen to our selected Hammond organ tunes playlist!

Many musicians and appreciators of the Hammond Organ don't know much about how much effort is required in producing that tone and feel. The idea here is to briefly expose each part of the Hammond B3 and show how it is often used in music.

What's Inside

Let's divide the Hammond Organ into three big parts: 1. Manuals (system of controls: double keyboard and pedalboard); 2. Tonewheel Generator (mechanical generator, Vibrato Scanner, motors, and filters), and 3. Preamplifier (electronic parts, preparing the audio before amplification).


The Hammond organ was built as a "portable and affordable alternative" for the pipe organ, some nomenclature comes from the pipe organ language. The keyboards, also called Manuals (Upper, Lower and pedalboard, which is a keyboard for the feet), contain a system of nine mechanical contacts per key that engage the harmonics produced by the tonewheel generator. The Drawbars are contact sliders located above the upper manual on the control rail, they adjust the amount of each harmonic to create a timbre. There are sets of nine drawbars to be combined in order to form a sound, two sets for each manual and two drawbars for the pedalboards.

Drawbar combinations are called registration. For example, in the organ language of jazz and soul jazz, different peculiar registrations are often used for each manual: in the Lower Keyboard, a deep and fluted sound registration allows playing left-hand bass notes (often combined with the pedalboard) and also serves as comping for the right-hand; in the Upper, a louder timbre with bright mid-and high-tones serves as a melody or solo voice and reinforces the comping sound. These are noticeable in most Hammond recordings with variations, of course. Here is a traditional soul jazz example of "Little Green Man" by Larry Goldings, Peter Bernstein and Bill Stewart from their recording Perpetual Pendulum (Smoke Session Records, 2022)

The control rail contains more buttons: Vibrato/Chorus Knob, Manual Tabs and Percussion Tabs. On the left side of each manual, you find an octave of "Preset Keys," another characteristic of the Hammond organ consoles. The "Preset Keys" are real keys with inverted black with white colors. When these keys are pressed down, they lock in the position and engage a stored registration; keys "C#" to "A" recall pre-arranged registrations previously adjusted inside the organ on the "Panel Preset." The notes "B" and "Bb" enable real time registration in each of the two drawbars sets; the C preset note is called "cancel" (release all presets). The organ player can switch between the presets with one touch, a new pressed note automatically releases the previous one.

The Vibrato Line is a set of capacitors and coils attached to the back of the Upper Manual (earlier versions had a separate box detached from the Manuals). Its function is to modify, split, and combine the signal coming from the Vibrato Scanner creating the Vibrato and Chorus effects. Also attached to the manual is the "Matching Transformer" that adjusts the low impedance audio coming from the mechanical tonewheel generator to high impedance going to the tube preamplifier and also taps/divides the signal into different intensity levels for the drawbars.


The synchronous motors used in electric clocks, which Laurens Hammond had manufactured earlier in the 1920s, were adapted to run a big generator gear. This motor is very stable and runs smoothly when properly oiled, spinning according to the power source frequency of 60 hertz in the Americas and specially converted organs to 50 hertz in Europe and most of Asia. Although it requires an additional start motor to drive the gear and the synchronous motor to the speed. The "turn on" procedure functions via the Start and Run buttons. The gear system has a center axis that allows several small transfer gears and wheels to rotate simultaneously. Each harmonic note is generated from its respective spinning wheel. The sizes and dents on each wheel determine the tone and octave pitch. When the wheel is spinning, it creates a magnetic field that is transformed into electrical voltage through a coil of wire aka "the pickup." The heavy Tonewheel Generator system with motors and scanner is mounted in the organ's cabinet by suspension springs to reduce noise and vibration. On the top of the generator, small filters tailor each frequency before going inside the manuals.

A round metal engine attached to the motor literally scans the organ sound to produce the Vibrato effect. The audio signal is sent to the rotor plates located at the center of the device, then is captured back by a series of stationary plates with spaces between them mounted around its circumference. As the motor runs, the rotor pallets move through the stationary ones and create a true mechanical vibrato effect. Audio signals from the vibrato line are combined inside a complex rotary switch (located under the control rail). This switch closes and opens several mechanical contacts, switching between different vibrato and chorus levels. The early model Hammond BC had an additional out-of-tune tonewheel generator to create the chorus effect when mixed with the main generator.

The Vibrato adds tension to the registration, resulting in a timbre full of expression and movement. In the song "Tighten Up" by Alice Carreri & Sidecar Trio, it's impossible not to notice the beautiful vibrato effect played by Danish organ player [[Dan Hemmer]].

The chorus is widely used to enhance the highest harmonics, this also creates a sense of space and brightness to the registration. When combined with the Leslie's rotary effect, it will result in sounds that can easily be described as "soulful" and "gospel." For example: The song "Happy" by Speedometer, or "God is Great" by the master Billy Preston features a preset with a very intense chorus with a full gospel registration.


The preamp is where the signal is treated, mixed, modulated and enhanced with functions like the percussive tone. Inside, there's a very clean (but clever) point to point tube preamp circuitry. Several stages of filters and envelopes used for effects processing will then work alongside the manual registrations and control the timbre of the instrument.

The percussion tone is a "ping" sound obtained with an envelope filter that borrows the highest pitch harmonic drawbar to do its magic It only works with the "Bb" registration in the upper manual and only gets triggered when played in staccato. It's controlled through switches for decay length and volume in two harmonic possibilities. This percussive pluck adds attack to the registration, and is often used in jazz music. You can clearly notice it in the theme of "Fly Me to The Moon" recorded by the beloved organ player (and genius) Joey DeFrancesco, who unfortunately left us too early in 2022. He used a light drawbar combination with a very pronounced Percussion Harmonic. You can hear the percussion tone decay. By the way, besides the percussion tone, the Hammond organ's sound has NO DECAY. As long you press the key, it will keep producing sound, until you release it.


Of course, we cannot forget about the keyboard, where it all starts. We are all familiar with piano keyboards, but it works a bit differently on Hammond organs. Loud and quiet sounds—pianissimo, fortissimo, and everything in between—are not achieved through the pressure applied on the keys, but rather through an expression pedal. Often mistaken for a common volume pedal, it doesn't only control the variation in volume, but also the overall tonality of the instrument.

Take a video tour inside and out of a restored B3 Hammond:

That's a Wrap

The Hammond World is huge and full of interesting things to be discovered. Like any other subject that has been around for nearly a century, the more you dig, the more you find, and that only fuels my passion for this amazing instrument. As a musician, I found my true expression in the Hammond organ, the infinite sustain and strong timbre possibilities made me want to learn everything I can about it, and that's why I've been dedicating decades of my life to playing and restoring these beautiful masterpieces: The Hammond Organs.

What about you? What do you feel when you hear the Hammond sound?

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