The original Hammond Organ was designed and built by the ex-
watchmaker Laurens Hammond 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. Hammonds 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 Telaharmonium: the tone weel. The
tone generator assembly consisted of an AC synchronous motor
connected to a geartrain 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. The Hammond had a unique drawbar system of additive
timbre synthesis (again a development of the Telharmoni