81/50
81/50, the (classical/diptolemaic) grave major third, is a syntonic comma sharp of 8/5, a Marveltwin comma (325/324) flat of 13/8, and merely a Palingenetic Comma (1701/1700) sharp of the interval 34/21. It can be obtained by stacking two classic minor sevenths (9/5) and subtracting an octave, or subtracting two small whole tones (10/9) from an octave.
| Interval information |