Semicomma
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
- Septimal kleisma
- Septimal semicomma
References
- v
- t
- e
Intervals
semitone
(post-Bach
Western)
| (Numbers in brackets are the number of semitones in the interval.) |
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tuning
systems
| 24-tone equal temperament (Numbers in brackets refer to fractional semitones.) |
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| Just intonations (Numbers in brackets refer to pitch ratios.) |
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intervals
| Groups | |
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| Semitones | |
| Quarter tones | |
| Commas |
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| Measurement |
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| Others |
