Among the first widely available electric instruments, the Hammond organ was named after its inventor, Laurens Hammond, in the year 1934. Hammond marketed the organ as an alternative to pianos in private homes, and as a low-cost option for ice rinks, ball parks, and churches in cases where pipe organs were prohibitively expensive. It was in churches that the Hammond organ found its most immediate success, and it was in churches that many of those who went on to make a name for themselves with the instrument first encountered it. During the late sixties and much of the seventies, the B3 became the default choice of keyboardists in rock, jazz, and blues.
The Hammond organ consists of two sets of keyboards, or "manuals." A series of "tonewheels" produces the synthesis of waveforms. A set of sliding drawbars are used to mix the various harmonic components generated by the tonewheels to synthesize a wide variety of sounds. Among the many Hammond models, the B3 model is the most popular. So much so, that it is considered the standard amongst Hammond organs, and the words "Hammond" and "B3" have become somewhat interchangeable. This is not generally problematic, as most popular Hammond organ models share many of the same functions as the B3, and in some cases are functionally identical. B3s have become commonly associated with the Leslie speaker cabinet. Though the Hammond company produced its own speakers (and many models had them built-in) the organs are now generally spoken of in the same breath as Leslie speakers, which contain rotating speaker elements that causes a modulation effect that has come to characterize many of the most famous B3 sounds.
The flexibility and power of the B3 lies in the special design of the drawbars which can be set individually by the organist either while playing or can be preset in one of the nine preset keys of the organ, located to the left of the two keyboard actions. The nine harmonics set by these drawbars can be mixed in such a way that many instrumental tones can be imitated by setting them in specific combinations. These drawbars, or "stops" are the origin of the popular phrase "pull out all the stops," which on the B3, (unlike on traditional pipe organs, where the action physically alters the lengths of the pipes, and causes a decidedly less musical sound) causes all of the tone wheel's harmonics to sound at their maximum potential - a very full and complex tone that can dominate a performance mix in nearly any genre.
The tone generator of Hammond tonewheel organs is electro-mechanical in function. The waveforms are generated by moving tone wheels instead of the electronic wave oscillators found in many synthesizers. The B3 has an assembly of 96 tone wheels, (91 of which are actually used in tone generation, the rest being used to properly space and balance the system) each magnetically generating one pitch of the first harmonic or one overtone among many. In operation, the evenly spaced "teeth" on the surface of the wheel rotate at a constant speed through the field of a magnetic pickup. Wheels with fewer teeth will generate a lower pitch when rotating at the same speed as wheels with more. It is the shape of the teeth and their movement past the pickup that generates the voltage that becomes the waveform for the organ.
This concept of mechanical audio synthesis was a development of experiments carried out in 1897 by inventor Thaddeus Cahill, who patented the electromechanical system, and used it on a massive, and extremely expensive instrument that he dubbed the Telharmonium. Though this creation never became popular (they were so large and expensive that only three were ever built) he paved the way for Laurens Hammond to introduce electronically synthesized sounds to the world stage. It was only a matter of time before the organs became almost ubiquitous, and cutting-edge artists like Steve Emerson, Steve Winwood, and Gregg Allman would begin to experiment with overdriving their organs to create unique and powerful sounds that have penetrated our culture.
The popularity of the Hammond B3 organ is characterized by the ubiquity of the song “Green Onions," recorded in 1962 by Booker T. and the MGs, which became a musical super hit in the early sixties, and remains one of the defining . Booker T. Jones is often thought of as a musical prodigy as he mastered playing a number of instruments like saxophone, trombone, oboe, and piano at an early age. He discovered the organ however, like so many others - in church. "Green Onions" was recorded in 1962, and the instantly-recognizable organ riff has become entrenched in our culture, appearing any time a music director needs something to sound cool.
The Hammond company today produces a line of products based on the success of their organ designs. Many of these new products incorporate digital technology to model the behavior and synthesis functions of mechanical tonewheels in a package that doesn't require multiple people to move. In 2002, Hammond introduced an organ dubbed the "New B3." While many modern revisions of classic instruments meet with harsh criticism from purists, the New B3's replication of the classic organ's action and tone is winning over some of the most successful organists in modern music, paving the way for a new explosion in popularity.
For more details of the Hammond organ, please browse these resources: