The Helmoltz Resonator

Origins

Experiments with electricity to create musical sound begin as early as 1759 when the French Jesuit priest Jean Baptiste Delaborde of Paris created an electrical harpsichord called the 'Clavecin Électrique' which was striclty speaking an 'electo-mechanical' instument, the device used a keyboard to control vibrating tunes strips to produce sounds. Experimental instruments incorporating solenoids, motors, and other electromechanical elements continued to be invented throughout the 19th century such as William Duddell's 'singing arc'. The German physicist, mathematician and author of the seminal work "Sensations Of Tone: Psychological Basis for Theory of Music" (c1860) Hermann Ludwig Ferdinand von Helmholtz (1821-1894)was the first physicist to undertake an analystical study of sound. Helmholtz created an electronically controlled device to analyse combinations of tones the "Helmholtz Resonator", using electromagnetically vibrating metal tines and glass or metal resonating spheres the machine could be used for analysing the constituent tones that create complex natural sounds. Helmholtz was concerned solely with the scientific analysis of sound and had no interest in direct musical applications. The theoretical musical ideas were provided by Ferruccio Busoni, the Italian composer and pianists who's influential essay "Sketch of a New Aesthetic of Music" was inspired by accounts of Thaddeus Cahill's 'Telharmonium'.

1870-1915: Early Experiments

The first electronic instruments built from 1870 to 1915 used a variety of techniques to generate sound: the tone wheel (used in the Telharmonium and the Chorelcello)- a rotating metal disk in a magnetic field causing variations in an electrical signal, an electronic spark causing direct fluctuations in the air (used uniquely in William Duddell's "Singing Arc' in 1899) and Elisha Grey's self vibrating electromagnetic circuit in the 'Electronic Telegraph', a spin-off from telephone technology. The tone wheel was to survive until the 1950's in the Hammond Organ but the experiments with self oscillating circuits and electric arcs were discontinued with the development of vacuum tube technology.

1915-1960: The Vacuum Tube Era.

The engineer and prolific US inventor Lee De Forest patented the first Vacuum tube or triode in 1906, a refinement of John A. Fleming's electronic valve. The Vacuum tube's main use was in radio technology but De Forest discovered that it was possible to produce audible sounds from the tubes by a process known as heterodyning. twentieth century by radio engineers experimenting with radio vacuum tubes. Heterodyning effect is created by two high radio frequency sound waves of similar but varying frequency combining and creating a lower audible frequency, equal to the difference between the two radio frequencies (approximately 20 Hz to 20,000 Hz). De Forest was one amongst several engineers to realise the musical potential of the heterodyning effect and in 1915 created a musical instrument, the "Audion Piano" . Other instruments to first exploit the vacuum tube were the 'Theremin' (1917) 'Ondes Martenot' (1928), the 'Sphäraphon' (1921) the 'Pianorad' (1926). The Vacuum tube was to remain the primary type of audio synthesis until the invention of the integrated circuit in the 1960's.

1960-1980: Integrated Circuits.

Integrated Circuits came into widespread use in the early 1960's. Inspired by the writings of the German instrument designer Harald Bode, Robert Moog, Donald Buchla and others created a new generation of easy to use, reliable and popular electronic instruments.

1980-present: Digital.

The next and current generation of electronic instruments were the digital synthesisers of the 1980s. These synthesisers were software controlled offering complex control over various forms of synthesis previously only available on extremely expensive studio synthesisers. Early models of this generation included the Yamaha DX range and the Casio CZ synthesisers.

© 120 Years Of Electronic Music 2005