1619edo
Theory
1619edo is excellent in the 13-limit, where it tempers out 4225/4224, 4375/4374, 6656/6655, 78125/78078, and 117649/117612. It also notably tempers out quartisma (117440512/117406179) and 123201/123200.
1619edo tunes keenanisma very finely, to 6 steps, and can use it as a microchroma. 1619edo has 7/6 on 360th step, a highly divisible number, 27/25 on 180th, and 33/32 on 72nd as a consequence of tempering out the commas. This means that 72ed33/32 is virtually equivalent to 1619edo. When it comes to using 33/32 as the generator, 1619edo supports the ravine temperament, which tempers out 196625/196608, 200000/199927, 2912000/2910897, and 3764768/3764475.
Since 33/32 is close to 1\45, 7\6 is close to 1\9, and 385/384 is close to 1\270, 1619edo can be thought of as 1620edo where one step was extracted and all others were moved into a more harmonically just position. It achieves this because 1620edo is contorted 270edo in the 11-limit, and its 13/8 is on the flat side coming from 324edo, and thus when it is octave stretched, steps sharpen enough to arrive at 1619edo's 13-limit excellence.
The Vidarines
1619edo supports vidar, which has the comma basis 4225/4224, 4375/4374, and 6656/6655. In addition, it contains a wealth of rank-two 13-limit temperaments that are produced by adding one comma on top of the vidar comma basis, such as decigrave, keenanose, moulin, etc. Eliora proposes the name The Vidarines for this collection of temperaments.
One such temperament is the keenanose temperament, which has comma basis 4225/4224, 4375/4374, 6656/6655, and 151263/151250. Keenanisma is the generator in the keenanose temperament, 270 & 1619, in which it highlights the relationship between 270 keenanismas and the octave. It also achieves this since 270 × 6 = 1620, and 1619 is 1 short of that and also excellent in the 13-limit.
Another temperament which highlights the interval relationships in 1619edo (and is also a member of The Vidarines collection) is 45 & 1619, and if it had a name, it would be called decigrave, since 10 steps make a 7/6, which is referred to as the grave minor third sometimes. It has a comma basis 4225/4224, 4375/4374, 6656/6655, [23 5 13 -23 1 0⟩ in the 13-limit. Its generator is 36 steps, which represents 65/64 and 66/65 tempered together, and 2 of them make 33/32. 5 of them make 27/25, and 10 of them make 7/6.
1619edo supports the 494 & 1619 temperament called moulin, which is also a member of The Vidarines collection. In this case, 91125/91091 has to be added to the three commas to produce a rank-2 temperament.
A quick summary is shown below.
| Temperament | Generator
associated ratio |
Completing comma |
|---|---|---|
| Keenanose | 385/384 | 151263/151250 |
| Decigrave | 66/65 ~ 65/64 | [23 5 13 -23 1 0⟩ |
| Moulin | 13/11 | 91125/91091 |
| 224 & 1619 | 256/175 | 18753525/18743296 |
| 901 & 1619 | 104/99 | 34875815625/34843787264 |
While abigail is a member of the vidarines, 1619edo does not support it because abigail is a period-2 temperament, and 1619 is an odd number.
Prime harmonics
| Harmonic | 2 | 3 | 5 | 7 | 11 | 13 | 17 | 19 | 23 | 29 | |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Error | Absolute (¢) | +0.000 | -0.040 | -0.149 | -0.080 | +0.134 | -0.009 | +0.295 | -0.293 | +0.262 | -0.053 |
| Relative (%) | +0.0 | -5.4 | -20.2 | -10.8 | +18.0 | -1.2 | +39.8 | -39.5 | +35.3 | -7.1 | |
| Steps (reduced) |
1619 (0) |
2566 (947) |
3759 (521) |
4545 (1307) |
5601 (744) |
5991 (1134) |
6618 (142) |
6877 (401) |
7324 (848) |
7865 (1389) | |
Miscellaneous properties
1619edo is the 256th prime edo.
Selected intervals
| Step | Cents | Ratio | Name* |
|---|---|---|---|
| 0 | 0.000 | 1/1 | prime, unison |
| 6 | 4.447 | 385/384 | keenanisma |
| 72 | 53.366 | 33/32 | al-Farabi quarter-tone |
| 360 | 266.831 | 7/6 | septimal subminor third |
| 1619 | 1200.000 | 2/1 | perfect octave |
* named in accordance to their most just 13-limit counterpart using the names accepted on the wiki.
Regular temperament properties
| Subgroup | Comma list | Mapping | Optimal 8ve stretch (¢) |
Tuning error | |
|---|---|---|---|---|---|
| Absolute (¢) | Relative (%) | ||||
| 2.3 | [-2566 1619⟩ | [⟨1619 2566]] | +0.0127 | 0.0127 | 1.71 |
| 2.3.5 | [-69 45 -1⟩, [-82 -1 36⟩ | [⟨1619 2566 3759]] | +0.0299 | 0.0265 | 3.57 |
| 2.3.5.7 | 4375/4374, 52734375/52706752, [-67 14 6 11⟩ | [⟨1619 2566 3759 4545]] | +0.0295 | 0.0229 | 3.09 |
| 2.3.5.7.11 | 4375/4374, 117649/117612, 759375/758912, [24 -6 0 1 -5⟩ | [⟨1619 2566 3759 4545 5601]] | +0.0159 | 0.0341 | 4.60 |
| 2.3.5.7.11.13 | 4225/4224, 4375/4374, 6656/6655, 78125/78078, 117649/117612 | [⟨1619 2566 3759 4545 5601 5991]] | +0.0136 | 0.0315 | 4.26 |
Rank-2 temperaments
| Periods per Octave |
Generator (Reduced) |
Cents (Reduced) |
Associated Ratio |
Temperaments |
|---|---|---|---|---|
| 1 | 6\1619 | 4.447 | 385/384 | Keenanose |
| 1 | 36\1619 | 26.683 | 65/64 ~ 66/65 | Decigrave |
| 1 | 72\1619 | 53.366 | 33/32 | Ravine |
| 1 | 390\1619 | 289.067 | 13/11 | Moulin |