Musical Engineers: Laurens Hammond

The neural links between music, math, and technology have long been studied and established, and a number of great inventors or engineers have had side interests in the arts. This post will delve into the life of Laurens Hammond, inventor of one of the most widely-heard electromechanical instruments of the 20^th century.

Laurens Hammond (usually referred to as "Larry") was a tinkerer from a young age, and this interest led him to pursue a mechanical engineering degree at Cornell University. After graduating in 1916, he worked for several Detroit-area automobile manufacturers, although he continued to invent on the side. In 1919 he invented a silent spring-driven clock, and in 1922 developed a 3-D motion picture projection system called the Teleview. Only one feature film was made for this system, and although it was a great critical success the economics of refitting theaters with new projection systems ended the Teleview's run.

While working on the Teleview, Hammond perfected his skill at designing and building increasingly small synchronous motors. In the late 1920s he used this skill to design an electric clock in which the motor was synchronized with the current frequency of the power grid, resulting in great precision so long as the current's frequency remained constant. Hammond patented his clock and formed the Hammond Clock Company, which eventually produced dozens of models and employed 700 people. Due to the Great Depression and problems with patent royalties, the company ran into financial problems in the mid-1930s. Hammond scrambled to invent a lucrative solution: he developed an electric bridge table that sold well enough to pay off outstanding debts, but this proved to be a short-lived solution.

Hammond had long toyed with the idea that his synchronous motors could be put to musical use. While developing the synchronous clock, he had stumbled upon the fact that if a gear is rotated within a magnetic field, it will theoretically produce a musical tone if connected to a speaker. (This was a sort of precursor to the concept of a guitar pickup.) If Hammond synchronized these "tone wheels" with the frequency of the power current, the instrument would perpetually stay in tune. Hammond gutted a used piano, worked with Hammond Clock's treasurer - who was a church organist - to develop suitable tones, and in 1933 completed his first "Hammond organ." The instrument contained 91 tone wheels, each of which was connected to nine switches. These switches activated different harmonics of each tone wheel fundamental, effectively producing nine different tones for each wheel. Using additive synthesis of different waveforms produced by the tone wheels, the instrument was capable of hundreds of different tones and musical colors. Hammond added drawbars, based on a church organ's register system, so that the performer could precisely select and alter the organ's range and sound on the fly.

Hammond patented the instrument in 1935, and it was an immediate success. Churches jumped on the Hammond organ because it was cheaper, lighter, and easier to maintain than traditional pipe organs, and could replicate many of the latter's complex layered sounds. The instrument eventually made its way into jazz and rock, is featured on various landmark recordings of the 60s and 70s and was revived in the 90s and 21^st century. Although Hammond developed his own corresponding speaker system, most Hammond players took to the Leslie speaker, which was built with a rotating horn to enable a swirling Doppler effect sound.

Hammond organs were eventually redesigned with transistor circuitry, but most players still gravitate to the antique tone wheel models. Interestingly, many design flaws that Laurens Hammond tried and failed to correct - such as a percussive key click and unintended crosstalk interference between rotating and stationary tone wheels - are now highly valued by studio musicians and collectors as integral parts of the instrument's sound.

Laurens Hammond was an eccentric fellow who never expected or enjoyed the fame his invention brought him. He was intimately involved in the Hammond Organ Company into his later life and also forayed into economics, publishing an 80-page pamphlet about mathematically eliminating unemployment; this publication understandably did not catch on. Hammond died in 1975 with over 100 patents to his name. I find it interesting that, whenever I appreciate the sound of a Hammond organ, I can thank Larry's bankrupt clock company and ingenious mind for its invention.

(Images via NNDB & AcesandEights)