Ragisma

Septimal minor third on C  Play .

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 ). It is also the difference between minor Bohlen–Pierce diesis (245:243) and septimal semicomma (126:125). ( Play )

Sources

1. Haluska, Jan (2003). The Mathematical Theory of Tone Systems, p.xxviii. ISBN 80-88683-28-9.