Ragisma

Septimal minor third on C Play (help·info).

In music and tuning, the ragisma is an interval with the ratio of 4375:4374,^[1] ≈0.396 cents (a superparticular ratio). It is usually defined as the difference between the septimal minor third (7:6) and two Bohlen–Pierce small semitones (27:25 Play one (help·info)). It is also the difference between minor Bohlen–Pierce diesis (245:243) and septimal semicomma (126:125), as well as the difference between the septimal third tone (28:27) and the greater diesis (648:625). (Play (help·info))

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