400edo: Difference between revisions
formalized the gregorian leap week, 71 & 400 temp |
|||
Line 13: | Line 13: | ||
400 factors into 2<sup>4</sup> × 5<sup>2</sup>, with subset edos {{EDOs| 2, 4, 5, 8, 10, 16, 20, 25, 40, 50, 80, 100, and 200 }}. Notably, 200edo holds a record for the best 3/2 fifth approximation. | 400 factors into 2<sup>4</sup> × 5<sup>2</sup>, with subset edos {{EDOs| 2, 4, 5, 8, 10, 16, 20, 25, 40, 50, 80, 100, and 200 }}. Notably, 200edo holds a record for the best 3/2 fifth approximation. | ||
400 is also the number of years in the Gregorian calendar's leap cycle. 400edo supports the GregorianLeapWeek[71] scale with 231\400 as the generator, which is close to 5/12 syntonic comma meantone. An interesting variation upon the scale | 400 is also the number of years in the Gregorian calendar's leap cycle. 400edo supports the GregorianLeapWeek[71] scale with 231\400 as the generator, which is close to 5/12 syntonic comma meantone. In the 19-limit, the generator corresponds to 525/352 and the comma basis is 969/968, 1001/1000, 2128/2125, 3328/3325, 4225/4224, and 444528/444125. An interesting variation upon the scale is the ISOWeek[71], which contains all the years which [[Wikipedia:ISO week date|have 53 weeks]] in the current calendar system. | ||
Likewise, 400edo contains GregorianLeapDay[97] scale, which is a [[maximal evenness]] version of the leap rule currently in use in the world today. The scale has a 33\400 generator which is associated to [[18/17]] and [[55/52]], and the corresponding temperament is 97 & 400, with comma list 2432/2431, 2601/2600, 2926/2925, 6175/6174, 17689/17680, and 22477/22440. | |||
=== Prime harmonics === | === Prime harmonics === | ||
Line 35: | Line 37: | ||
| 33 | | 33 | ||
| small septendecimal semitone | | small septendecimal semitone | ||
| [[18/17]] | | [[18/17]], [[55/52]] | ||
|- | |- | ||
| 35 | | 35 | ||
Line 59: | Line 61: | ||
| 231 | | 231 | ||
| Gregorian leap week fifth | | Gregorian leap week fifth | ||
| | | 525/352, 3/2 / (81/80)^(5/12) | ||
|- | |- | ||
| 234 | | 234 | ||
Line 164: | Line 166: | ||
| 125/96 | | 125/96 | ||
| [[Majvamic]] | | [[Majvamic]] | ||
|- | |||
|1 | |||
|169\400 | |||
|507.00 | |||
|525/352 | |||
|[[Gregorian leap week]] | |||
|- | |- | ||
| 2 | | 2 |