Semicomma

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Semicomma on C About this sound 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 3^3\cdot5^7:2^{21}. This is a ratio of approximately 1:1.0058283805847168, or about 10.06 cents[2] (About this sound Play ). It is derived from the difference in pitch between three 75/64 just augmented seconds (About this sound Play just augmented second ) and one 8/5 just minor sixth (About this sound Play minor sixth ) begun on the same root ((3 × 274.58) - (1 × 813.69) = 823.74 - 813.69 = 10.05 cents).[3]

See also[edit]

Sources[edit]

  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", Xenharmonic.