A Few Notes on the Hammond Organ

Premiere of "For Jimmy"

In memory of James Oscar Smith 1925(1928?) - 2005

Hammond Forever!

Long-time Hammond lovers and aficionados will be aware of most, if not all, of the contents of this page. But for those who have recently discovered the marvelous growl of this gigantic beast,either through CD, MTV and VH1 or through actual exposure to the real thing, here are some "factoids" to amuse and enlighten.
By the way, all opinions on this site are my own, and based on the model of the contemporary jazz organist. Those who play classical, pop or rock organ may disagree with some or all of this - that's cool with me...

Quick Historical Reference

The Hammond organ was the brainchild of Laurens Hammond, who introduced the first Model A in 1935. The standard Hammond consists of two keyboards, or "manuals", of 61 notes each, plus a 25-note pedalboard. There is also a full concert model RT, with AGO 32-note radial pedalboard, which is seldom seen in the night club circuit, probably due to the excess weight and the typical manner jazz players use the pedals. Spinet models are significantly deficient in both keys and pedals - IMHO it's not possible to play the true grooving jazz styles on these instruments, as the bass line cannot be performed on the short keyboards.

The actual design of the Hammond tonewheel came from Thaddeus Cahill's Telharmonium, pictured above. When the Hammond was first introduced, the year after the death of Cahill, the survivors of the estate who never had appreciated the use of the family fortune to fund the behemoth Telhamonium, chose to not pursue the patent violation, in effect saying, "Let him have it." Thus the instrument is not known as the Cahill B-3...

Turn It On

One does not simply turn on a Hammond organ like a toaster or light switch - not this lady! There are two switches, labeled Start and Run, on the upper right of the console. Start activates a starting motor, similar in purpose to an automobile engine starter. Its job is to get the main motor spinning so it can run on its own.

Turn it On cont'd...

With the Run switch in the off position, push the Start switch forward. You will hear a whirring as the start motor spins up. After a brief time (1-10 seconds) you should hear a change of timbre as the start motor engages the tonewheel motor. Continue to hold the Start switch until the main motor comes up to speed, usually another 5-10 seconds. Keeping the Start switch On, turn the Run switch to the On position and hold for another 2-5 seconds, then release both switches. The Start switch will return to the Off position, and the main motor will be running. When the tubes have warmed up (another 30 seconds or so), you're ready to play.

There! Easy wasn't it?

The Sound

The signature sound of the Hammond is produced by a set of 91 "tonewheels" with precisely cut notches that rotate within magnetic fields. This magnetic interference produces a nearly-sinusoidal tone (flute-like) that is the foundation of the magnificent Hammond sound. The tonewheels are combined in an assembly known as the 'tone generator'. Although it was never openly admitted, Laurens Hammond got the tonewheel concept from a much larger (20 railway boxcars!)machine known as the Telharmonium (see the picture above right, click the links to hear and see the real monster in action.)

For a given sound, or registration, a set of 9 drawbars, which correspond to different harmonics, or pitches, may be adjusted to create a unique timbre, the process is analogous to that of a fixed-envelope additive synthesizer. More information on this process may be found on my Original Registrations page. For additional warmth and color, a knob provides three levels of Vibrato, with or without Chorus, a form of timbre and pitch change.

Jazz players demand the B-3 model, although knowledgable players also like the A-100 series. The reason for this is the Hammond percussion, a unique bell-like addition to the basic tone that adds drive and distinction to the sound. Earlier models lacked this vital feature (though there is a way to add it to those boxes.)

The Leslie Tone Cabinet

Another integral part of the jazz Hammond sound is the Leslie tone cabinet, with its distinctive whirling effect. The result of rotating the output of the upper and lower speakers independently, the sound appears to come from a much wider acoustic space than just a simple speaker cabinet. There are three possible variations to this - no rotation, slow, or "chorale" motion, and the rapid "tremolo" which defines the sound.

The Beast

The final component of the B-3 experience is the nature of the beast itself. The lady is a 325-plus pound mechanical monster, with precisely spinning wheels, electronic components like the sci-fi movies of the early '50s, and long clusters of wire. These interact to produce a particular background noise containing tone generator leakage, key clicks, and the whirr of the motors. The classic Hammond 'growl' is provided by a combination of all these things, and despite the best efforts of contemporary synthesizer manufacturers, has proved surprisingly resistant to emulation.

Long Live King Hammond (or perhaps Queen Hammond, as most organists seem to refer to their instruments as 'she'...)

Meet the Masters

And so many other masterful players: Groove Holmes, Jimmy McGriff, Jack McDuff, Hank Marr, Larry Young, Larry Goldings, the list goes on and on, and is still growing by the day. Hammond lives!