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Semicomma on C Play .

The semicomma, [1] also Fokker's comma (after 31-TET pioneer Adriaan Fokker), is type of small musical interval, or comma, in microtonal music equivalent to 2109375:2097152, [1] or 33×57 : 221. This is a ratio of approximately 1:1.0058283805847168, or about 10.06 cents [2] ( Play ). It is derived from the difference in pitch between three 75:64 just augmented seconds ( Play just augmented second ) and one 8:5 just minor sixth ( Play minor sixth ) begun on the same root ((3 × 274.58) − (1 × 813.69) = 823.74 − 813.69 = 10.05 cents). [3] It can also be viewed as the amount by which three tritaves exceed seven minor sixths.

See also

References

  1. ^ a b Haluska, Jan (2003). The Mathematical Theory of Tone Systems, p.xxix. ISBN  80-88683-28-9.
  2. ^ " List of Intervals", Huygens-Fokker.org.
  3. ^ " Semicomma", on Xenharmonic Wiki.