text: Thaddeus Cahill's gargantuan and controversial instrument, the Telharmonium, which began piping music to New York City establishments over the telephone system in 1897, predated the advent of electronics, yet was the first instrument to demonstrate the use of the combination of many different pure electrical waveforms to synthesize real-world instrument sounds. Cahill's techniques were later used by Laurens Hammond in his organ design, and the 200-ton Telharmonium served as the world's first demonstration of electrically produced music on a grand scale.
  Meanwhile, some further experimentation with producing sound by electric impulses was taking place, especially in France.
  (1930s–1975)
  After the failure of the Telharmonium business, similar designs called tonewheel organs were continuously developed; For example:
  Robb Wave Organ by Morse Robb (Canada) — developed since c.1923, marketed 1936–1941
  Rangertone by Richard Ranger (United States) — marketed c.1932
  Hammond organ by Laurens Hammond and John M. Hanert (United States) — invented in 1934, marketed 1935–1975 (as the tonewheel organs)
  by Edwin Welte, et al. (Germany) — optical-tonewheel sampling organ, marketed 1935–1940s
  One of the earlier electric tonewheel organs was conceived and manufactured by Morse Robb, of the Robb Wave Organ Company. Built in Belleville, Ontario, the Robb Wave Organ predates its much more successful competitor Hammond by patent and manufacture, but shut down its operations in 1938 due to lack of funding.
  The first widespread success in this field was a product of the Hammond Clock Company in 1934. The Hammond organ quickly became the successor of the reed organ, displacing it almost completely.