4afdo
4ado is the arithmetic equal division of the octave into four parts of 1/4 each. 4ado is perhaps the smallest ADO that contains useful intervals for harmony, containing the major third, perfect fifth, and harmonic seventh. It is just barely large enough to be usable as a scale.
Intervals
| # | Cents | Ratio | Interval name |
|---|---|---|---|
| 0 | 0 | 1/1 | perfect unison |
| 1 | 386.3 | 5/4 | just major third |
| 2 | 702.0 | 3/2 | just perfect fifth |
| 3 | 968.8 | 7/4 | harmonic seventh |
| 4 | 1200.0 | 2/1 | perfect octave |