The ‘Hammond Organ’. Laurens Hammond, USA, 1935

The original Hammond Organ was Designed and built by the ex-watchmaker Laurens Hammond and  John M Hanert in April 1935. Hammond set up his ‘Hammond Organ Company’ in Evanston, Illinois to produce electronic organs for the ‘leisure market’ and in doing so created one of the most popular and enduring electronic instruments ever built.
Hammond’s machine was designed using technology that relates directly to Cahill’s ‘Telharmonium’ of 1900, but, on a much smaller scale. The Hammond organ generated sounds in the same way as the Telharmonium, the tone wheel – The tone generator assembly consisted of an AC synchronous motor connected to a gear train which drove a series of tone wheels, each of which rotated adjacent to a magnet and coil assembly. The number of bumps on each wheel in combination with the rotational speed determined the pitch produced by a particular tone wheel assembly. The pitches approximate even-tempered tuning.
This method of creating tones was maintained  until the mid 1960’s when transistors replaced tone wheels
The Hammond had a unique drawbar system of additive timbre synthesis (again a development of the Telharmonium) and stable intonation – a perennial problem with electronic instruments of the time. A note on the organ consisted of the fundamental and a number of harmonics, or multiples of that frequency. In the Hammond organ, the fundamental and up to eight harmonics were available and were controlled by means of drawbars and preset keys or buttons.A Hammond console organ included two 61-key manuals; the lower, or Great, and upper, or Swell, and a pedal board consisting of 25 keys. The concert models had a 32-key pedalboard. Hammond also patented an electromechanical reverb device using the helical torsion of a coiled spring, widely copied in later electronic instruments.
As well as being a successful home entertainment instrument, The Hammond Organ became popular with Jazz, Blues and Rock musicians up until the late 1970’s and was also used by ‘serious’ musicians such as Karlheinz Stockhausen in “Mikrophonie II”

Hammond patent documents

6 thoughts on “The ‘Hammond Organ’. Laurens Hammond, USA, 1935”

  1. Thanks a lot for this great source of information!
    A couple of possible typos:
    – “Telaharmonium” should be “Telharmonium”
    – “Karheinz” should be “Karlheinz”

  2. Here (under Hammond) you say the Tellharmonium was of 1900, but it’s 1897–and on your left menu that makes it hard to find. Because the left menu moves while moving the right side for reading, it’s easy to get lost.

  3. Excellent website, Simon! I have a webpage describing in detail the mathematics of the tuning of the 1930s-to-1960s tonewheel Hammonds, showing exactly how closely it approximates 12-tone equal-temperament (known among modern tuning theorists and microtonal musicians as 12ed2 or 12edo). It is classified as a RI (rational intonation), the larger umbrella which includes JI (just intonation) as a subset.

Leave a Reply

Your email address will not be published. Required fields are marked *