Ploidacot/Omega-tetracot
| Pergen | [P8, P4/4] |
| Numeral form | 3-sheared 4-cot |
| Pure generator size | 124.51 ¢ |
| Pure period size | 1200 ¢ |
| Forms | 9, 10, 19, 29 |
| Characteristic multival entry | 4 |
Omega-tetracot is a temperament archetype where the generator is a wide semitone, four of which make a perfect fourth of 4/3, and the period is a 2/1 octave. Omega-tetracot temperaments typically generate the 9L 1s and 10L 9s MOS scales, and containing all alpha-dicot intervals.
Intervals and notation
There is no agreed-upon notation for omega-tetracot, and constructing one by extending Pythagorean notation is complicated due to the fact that it does not split the chromatic or diatonic semitone, but rather the inversed double-diminished second (the difference between two chromatic semitones and one diatonic semitone). Note and interval names are provided where omega-tetracot intervals align with standard monocot intervals (which use chain-of-fifths notation).
| # | Cents | Notation | Name |
|---|---|---|---|
| −12 | 905.87 | A | major sixth |
| −11 | 1030.38 | ||
| −10 | 1154.89 | ||
| −9 | 79.40 | ||
| −8 | 203.91 | D | major second |
| −7 | 328.42 | ||
| −6 | 452.93 | ||
| −5 | 577.44 | ||
| −4 | 701.96 | G | perfect fifth |
| −3 | 826.47 | ||
| −2 | 950.98 | ||
| −1 | 1075.49 | ||
| 0 | 0.00 | C | perfect unison |
| 1 | 124.51 | ||
| 2 | 249.02 | ||
| 3 | 373.53 | ||
| 4 | 498.04 | F | perfect fourth |
| 5 | 622.56 | ||
| 6 | 747.07 | ||
| 7 | 871.58 | ||
| 8 | 996.09 | Bb | minor seventh |
| 9 | 1120.60 | ||
| 10 | 45.11 | ||
| 11 | 169.62 | ||
| 12 | 294.13 | Eb | minor third |
Temperament interpretations
An obvious interpretation for omega-tetracot is negri, where the generator is 16/15~15/14 and four of them make a perfect fourth. There are some extensions for full 11- and 13-limit: negri (10 & 19), negril (10e & 19), negric (9 & 19e), and negroni (10 & 19e).