648/625
| Interval information |
major diesis
Quadgu comma
[sound info]
The interval 648/625 is known as the diminished comma or major diesis. It is the amount by which four 6/5 minor thirds exceed an octave, in other words (6/5)4 / 2. This is approximately one step of 19edo, which is the amount by which four 19edo minor thirds exceed an octave. Tempering it out leads to 5-limit diminished temperament.