7L 3s (4/1-equivalent)
↖ 6L 2s⟨4/1⟩ | ↑ 7L 2s⟨4/1⟩ | 8L 2s⟨4/1⟩ ↗ |
← 6L 3s⟨4/1⟩ | 7L 3s (4/1-equivalent) | 8L 3s⟨4/1⟩ → |
↙ 6L 4s⟨4/1⟩ | ↓ 7L 4s⟨4/1⟩ | 8L 4s⟨4/1⟩ ↘ |
┌╥╥╥┬╥╥┬╥╥┬┐ │║║║│║║│║║││ ││││││││││││ └┴┴┴┴┴┴┴┴┴┴┘
sLLsLLsLLL
7L 3s<4/1> (sometimes called diaquadic) refers to a non-octave MOS scale family with a period of a 4/1 and which has 7 large and 3 small steps. These scales are in some ways a double octave clone of diatonic scales because they are generated from perfect fifths and have the 7edo/7ed4 685-cent flat fifth and 5edo/10ed4's 720-cent sharp fifth at the ends of the tuning spectrum. However, ~3/2 is now the chroma-negative rather than chroma-positive generator, equalized and collapsed tunings are now swapped (equalized is 720-cent fifth and collapsed is 685-cent fifth), and the basic tuning is now the 705-cent gentle fifth from 17edo/17ed4 instead of 12edo's fifth. Diaquadic scales are also more widely spaced than diatonic scales, closer melodically to an octave-period pentatonic scale.
Intervals
Dark generators | Notation | 17ed4 cents | Bright generators | Notation | 17ed4 cents | |||
---|---|---|---|---|---|---|---|---|
0 | C | perfect 0-step | 0.00 | 0 | C | perfect 10-step | 0.00 | |
1 | F | perfect 3-step | 705.90 | 1 | K | perfect 7-step | 1694.16 | |
2 | Jb | minor 6-step | 1411.80 | 2 | E | major 4-step | 988.26 | |
3 | Bb | minor 9-step | 2117.70 | 3 | D | major 1-step | 282.36 | |
4 | Eb | minor 2-step | 423.54 | 4 | A | major 8-step | 1976.52 | |
5 | Hb | minor 5-step | 1129.44 | 5 | H | major 5-step | 1270.62 | |
6 | Ab | minor 8-step | 1835.34 | 6 | E | major 2-step | 564.72 | |
7 | Db | minor 1-step | 141.18 | 7 | B | major 9-step | 2258.88 | |
8 | Gb | minor 4-step | 847.08 | 8 | J | major 6-step | 1552.98 |
Modes
The darker modes contain both major triads and augmented triads on the root, and the brighter modes contain both minor and diminished triads on the root.
- LLLsLLsLLs 9|0
- LLsLLLsLLs 8|1
- LLsLLsLLLs 7|2
- LLsLLsLLsL 6|3
- LsLLLsLLsL 5|4
- LsLLsLLLsL 4|5
- LsLLsLLsLL 3|6
- sLLLsLLsLL 2|7
- sLLsLLLsLL 1|8
- sLLsLLsLLL 0|9
Scale tree
Generator(ed4/1) | Cents | Step ratio | Comments | |||||||
---|---|---|---|---|---|---|---|---|---|---|
Bright | Dark | L:s | Hardness | |||||||
7\10 | 1680.000 | 720.000 | 1:1 | 1.000 | Equalized 7L 3s⟨4/1⟩ | |||||
40\57 | 1684.211 | 715.789 | 6:5 | 1.200 | ||||||
33\47 | 1685.106 | 714.894 | 5:4 | 1.250 | ||||||
59\84 | 1685.714 | 714.286 | 9:7 | 1.286 | ||||||
26\37 | 1686.486 | 713.514 | 4:3 | 1.333 | Supersoft 7L 3s⟨4/1⟩ | |||||
71\101 | 1687.129 | 712.871 | 11:8 | 1.375 | ||||||
45\64 | 1687.500 | 712.500 | 7:5 | 1.400 | ||||||
64\91 | 1687.912 | 712.088 | 10:7 | 1.429 | ||||||
19\27 | 1688.889 | 711.111 | 3:2 | 1.500 | Soft 7L 3s⟨4/1⟩ | |||||
69\98 | 1689.796 | 710.204 | 11:7 | 1.571 | ||||||
50\71 | 1690.141 | 709.859 | 8:5 | 1.600 | ||||||
81\115 | 1690.435 | 709.565 | 13:8 | 1.625 | ||||||
31\44 | 1690.909 | 709.091 | 5:3 | 1.667 | Semisoft 7L 3s⟨4/1⟩ Quarchy is around here | |||||
74\105 | 1691.429 | 708.571 | 12:7 | 1.714 | ||||||
43\61 | 1691.803 | 708.197 | 7:4 | 1.750 | ||||||
55\78 | 1692.308 | 707.692 | 9:5 | 1.800 | ||||||
12\17 | 1694.118 | 705.882 | 2:1 | 2.000 | Basic 7L 3s⟨4/1⟩ Scales with tunings softer than this are proper | |||||
53\75 | 1696.000 | 704.000 | 9:4 | 2.250 | ||||||
41\58 | 1696.552 | 703.448 | 7:3 | 2.333 | ||||||
70\99 | 1696.970 | 703.030 | 12:5 | 2.400 | ||||||
29\41 | 1697.561 | 702.439 | 5:2 | 2.500 | Semihard 7L 3s⟨4/1⟩ | |||||
75\106 | 1698.113 | 701.887 | 13:5 | 2.600 | ||||||
46\65 | 1698.462 | 701.538 | 8:3 | 2.667 | ||||||
63\89 | 1698.876 | 701.124 | 11:4 | 2.750 | ||||||
17\24 | 1700.000 | 700.000 | 3:1 | 3.000 | Hard 7L 3s⟨4/1⟩ Tetrominant is around here | |||||
56\79 | 1701.266 | 698.734 | 10:3 | 3.333 | ||||||
39\55 | 1701.818 | 698.182 | 7:2 | 3.500 | ||||||
61\86 | 1702.326 | 697.674 | 11:3 | 3.667 | ||||||
22\31 | 1703.226 | 696.774 | 4:1 | 4.000 | Superhard 7L 3s⟨4/1⟩ Meanquad is around here | |||||
49\69 | 1704.348 | 695.652 | 9:2 | 4.500 | ||||||
27\38 | 1705.263 | 694.737 | 5:1 | 5.000 | ||||||
32\45 | 1706.667 | 693.333 | 6:1 | 6.000 | ||||||
5\7 | 1714.286 | 685.714 | 1:0 | → ∞ | Collapsed 7L 3s⟨4/1⟩ |
Temperaments
There are two major rank-2 temperament interpretations of diaquadic, corresponding to double octave clones of meantone and archy.
Meanquad
Main article: Meanquad
- Subgroup: 4.5.6
- Comma list: 81/80
- Mapping: [⟨1 0 1], ⟨0 4 1]]
- Supporting ETs: 7, 31, 38, 24, 17, 10, 69, 45, 55, 11[-5], 52, 41, 13[+5], 27[+5]
- CTE tuning: ~3/2 = 697.214
Tetrominant
- Subgroup: 4.5.6.7
- Comma list: 36/35, 64/63
- Mapping: [⟨1 0 1 2], ⟨0 4 1 -2]]
- Supporting ETs: 7, 17, 24, 10, 31, 41, 27[+5], 38[+7], 55[+7], 58[+5, +7], 65[+5, +7], 44[+5], 75[+5, +7]
- CTE tuning: ~3/2 = 699.622
Quarchy
- Subgroup: 4.6.7
- Comma list: 64/63
- Mapping: [⟨1 2 0], ⟨0 1 -2]]
- Supporting ETs: 10, 17, 7, 27, 37, 44, 13, 24, 47, 11[+7], 23, 57, 16, 41
- CTE tuning: ~3/2 = 709.595