5L 2s (3/1-equivalent)
5L 2s⟨3/1⟩ is a 3/1-equivalent (tritave-equivalent) moment of symmetry scale containing 5 large steps and 2 small steps, repeating every interval of 3/1 (1902.0 ¢). Generators that produce this scale range from 1086.8 ¢ to 1141.2 ¢, or from 760.8 ¢ to 815.1 ¢.
| ↖ 4L 1s⟨3/1⟩ | ↑ 5L 1s⟨3/1⟩ | 6L 1s⟨3/1⟩ ↗ |
| ← 4L 2s⟨3/1⟩ | 5L 2s (3/1-equivalent) | 6L 2s⟨3/1⟩ → |
| ↙ 4L 3s⟨3/1⟩ | ↓ 5L 3s⟨3/1⟩ | 6L 3s⟨3/1⟩ ↘ |
sLLsLLL
Name
The name triatonic was coined by CompactStar, and is a back-formation from "diatonic" with di- being interpreted as 2 (the octave) and replaced with tri- for 3 (the tritave).
Theory
As a macrodiatonic scale
It is the macrodiatonic scale with the period of a tritave. This means it is a diatonic scale, but has octaves stretched out to the size of a tritave. Other intervals are also stretched in a way that makes the unrecognizable–the diatonic fifth is now the size of a major seventh. Interestingly, 19edt, an approximation of 12edo, has a tuning of this scale, meaning it contains both a diatonic scale (which approximates 12edo's diatonic scale) and a triatonic scale.
Temperament interpretations
Although they have not been studied in detail, it is possible to construct no-twos rank-2 temperament interpretations of this scale, such as the as-of-yet unnamed b12 & b5 temperament in the 3.13.17 subgroup, in which the generator (the stretched counterpart of the fifth) is ~17/9 and a stack of 4 generators tritave-reduced (the stretched counterpart of the major third) is ~13/9. See also the page for 12edt.
Modes
The modes have step patterns which are the same as the modes of the diatonic scale.
| UDP | Cyclic order |
Step pattern |
|---|---|---|
| 6|0 | 1 | LLLsLLs |
| 5|1 | 5 | LLsLLLs |
| 4|2 | 2 | LLsLLsL |
| 3|3 | 6 | LsLLLsL |
| 2|4 | 3 | LsLLsLL |
| 1|5 | 7 | sLLLsLL |
| 0|6 | 4 | sLLsLLL |
Scale degrees
| UDP | Cyclic order |
Step pattern |
Scale degree (mosdegree) | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | |||
| 6|0 | 1 | LLLsLLs | Perf. | Maj. | Maj. | Aug. | Perf. | Maj. | Maj. | Perf. |
| 5|1 | 5 | LLsLLLs | Perf. | Maj. | Maj. | Perf. | Perf. | Maj. | Maj. | Perf. |
| 4|2 | 2 | LLsLLsL | Perf. | Maj. | Maj. | Perf. | Perf. | Maj. | Min. | Perf. |
| 3|3 | 6 | LsLLLsL | Perf. | Maj. | Min. | Perf. | Perf. | Maj. | Min. | Perf. |
| 2|4 | 3 | LsLLsLL | Perf. | Maj. | Min. | Perf. | Perf. | Min. | Min. | Perf. |
| 1|5 | 7 | sLLLsLL | Perf. | Min. | Min. | Perf. | Perf. | Min. | Min. | Perf. |
| 0|6 | 4 | sLLsLLL | Perf. | Min. | Min. | Perf. | Dim. | Min. | Min. | Perf. |
Notation
Being a macrodiatonic scale, it can notated using the traditional diatonic notation, if all intervals are reinterpreted as their stretched versions (like octaves as tritaves). However, this approach involves 1-based indexing for a non-diatonic MOS which is generally discouraged. Alternatively, a generic MOS notation may be used like diamond MOS notation, which enables 0-based indexing at the cost of obscuring the connection to the standard diatonic scale.
Scale tree
| Template: Scale tree is deprecated. Please use Template: MOS tuning spectrum instead.
Details: Use of a single Comments parameter has become unmaintainable. Existing scale trees should be migrated to the new template, where comments are entered using a step ratio p/q as a parameter: {{MOS tuning spectrum
| 3/2 = Example comment
| 4/3 = Another example comment
}}
|
| Generator(edt) | Cents | Step ratio | Comments | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Bright | Dark | L:s | Hardness | |||||||
| 4\7 | 1086.831 | 815.124 | 1:1 | 1.000 | Equalized 5L 2s⟨3/1⟩ | |||||
| 23\40 | 1093.624 | 808.331 | 6:5 | 1.200 | ||||||
| 19\33 | 1095.065 | 806.890 | 5:4 | 1.250 | ||||||
| 34\59 | 1096.042 | 805.913 | 9:7 | 1.286 | ||||||
| 15\26 | 1097.282 | 804.673 | 4:3 | 1.333 | Supersoft 5L 2s⟨3/1⟩ | |||||
| 41\71 | 1098.312 | 803.643 | 11:8 | 1.375 | ||||||
| 26\45 | 1098.907 | 803.048 | 7:5 | 1.400 | ||||||
| 37\64 | 1099.568 | 802.387 | 10:7 | 1.429 | ||||||
| 11\19 | 1101.132 | 800.823 | 3:2 | 1.500 | Soft 5L 2s⟨3/1⟩ | |||||
| 40\69 | 1102.583 | 799.372 | 11:7 | 1.571 | ||||||
| 29\50 | 1103.134 | 798.821 | 8:5 | 1.600 | ||||||
| 47\81 | 1103.604 | 798.351 | 13:8 | 1.625 | ||||||
| 18\31 | 1104.361 | 797.594 | 5:3 | 1.667 | Semisoft 5L 2s⟨3/1⟩ | |||||
| 43\74 | 1105.190 | 796.765 | 12:7 | 1.714 | ||||||
| 25\43 | 1105.788 | 796.167 | 7:4 | 1.750 | ||||||
| 32\55 | 1106.592 | 795.363 | 9:5 | 1.800 | ||||||
| 7\12 | 1109.474 | 792.481 | 2:1 | 2.000 | Basic 5L 2s⟨3/1⟩ Scales with tunings softer than this are proper | |||||
| 31\53 | 1112.464 | 789.491 | 9:4 | 2.250 | ||||||
| 24\41 | 1113.340 | 788.615 | 7:3 | 2.333 | ||||||
| 41\70 | 1114.002 | 787.953 | 12:5 | 2.400 | ||||||
| 17\29 | 1114.939 | 787.016 | 5:2 | 2.500 | Semihard 5L 2s⟨3/1⟩ | |||||
| 44\75 | 1115.814 | 786.141 | 13:5 | 2.600 | ||||||
| 27\46 | 1116.365 | 785.590 | 8:3 | 2.667 | ||||||
| 37\63 | 1117.021 | 784.934 | 11:4 | 2.750 | ||||||
| 10\17 | 1118.797 | 783.158 | 3:1 | 3.000 | Hard 5L 2s⟨3/1⟩ | |||||
| 33\56 | 1120.795 | 781.160 | 10:3 | 3.333 | ||||||
| 23\39 | 1121.666 | 780.289 | 7:2 | 3.500 | ||||||
| 36\61 | 1122.465 | 779.490 | 11:3 | 3.667 | ||||||
| 13\22 | 1123.883 | 778.073 | 4:1 | 4.000 | Superhard 5L 2s⟨3/1⟩ | |||||
| 29\49 | 1125.647 | 776.308 | 9:2 | 4.500 | ||||||
| 16\27 | 1127.084 | 774.871 | 5:1 | 5.000 | ||||||
| 19\32 | 1129.286 | 772.669 | 6:1 | 6.000 | ||||||
| 3\5 | 1141.173 | 760.782 | 1:0 | → ∞ | Collapsed 5L 2s⟨3/1⟩ | |||||