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This article is about frequencies in dynamics. For subharmonic functions in mathematics, see Subharmonic function.
5-limit Otonality and Utonality: overtone and "undertone" series,[1] partials 1-5 numbered About this sound Play Otonality , About this sound Play Utonality , About this sound Play major chord on C , and About this sound Play minor chord on F .

In music and dynamics, subharmonic or undertone frequencies are frequencies below the main frequency of a signal.

Subharmonic frequencies are frequencies below the fundamental frequency of an oscillator in a ratio of 1/n, with n a positive integer number. For example, if the fundamental frequency of an oscillator is 440 Hz, sub-harmonics include 220 Hz (1/2), ~146.6 Hz (1/3) and 110 Hz (1/4). Thus, they are a mirror image of the harmonic series, the undertone series.

Subharmonics can be produced by signal amplification through loudspeakers.[2] They are naturally produced by bells, giving them their distinct sound.

String quartets by composers George Crumb and Daniel James Wolf[citation needed] as well as works by violinist and composer Mari Kimura require string instrument players to bow with sufficient pressure that the strings vibrate [3][clarification needed] causing the sound waves to modulate and demodulate by the instruments resonating horn with frequencies corresponding to subharmonics. The tritare, a guitar with Y shaped strings, cause subharmonics too. This can also be achieved by the extended technique of crossing two strings as some experimental jazz guitarists have developed. Also third bridge preparations on guitars cause timbres consisting of sets of high pitched overtones combined with a subharmonic resonant tone of the unplugged part of the string.

See also[edit]


  1. ^ Rehding, Alexander (2003). Hugo Riemann and the Birth of Modern Musical Thought, p.16. ISBN 978-0-521-82073-8. Goes to partial nine, unnumbered.
  2. ^ Barry Truax, ed (1999). Handbook for Acoustic Ecology. World Soundscape Project, Simon Fraser University. 
  3. ^ Edward Rothstein (April 21, 1994). "A Violinist Tests Limits In Music Of Her Time". New York Times. Retrieved 2008-09-15. 

Further reading[edit]

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