Whitewood: Difference between revisions

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Intervals: add for symmetry
Major and minor -> up and down
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| Generators tuning = 392.7
| Generators tuning = 392.7
| Optimization method = CWE
| Optimization method = CWE
| MOS scales = [[7L 7s]], [[7L 14s]], ...
| MOS scales = [[7L 7s]], [[7L 14s]],
| Pergen = (P8/7, ^1)
| Pergen = (P8/7, ^1)
| Color name = Lawati
| Color name = Lawati
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| Odd limit 2 = 9 | Mistuning 2 = 40.6 | Complexity 2 = 21
| Odd limit 2 = 9 | Mistuning 2 = 40.6 | Complexity 2 = 21
}}
}}
'''Whitewood''' is the [[rank-2 temperament]] tempering out [[2187/2048]], the Pythagorean chromatic semitone. As a result, the [[circle of fifths]] is the same as that of [[7edo]], and every interval on the chain of fifths is [[neutral (interval quality)|neutral]] in quality. The whitewood temperament adds prime [[5/1|5]] as an independent [[generator]], adding major and minor intervals on either side of the neutral ones.
'''Whitewood''' is the [[rank-2 temperament]] tempering out [[2187/2048]], the Pythagorean chromatic semitone. As a result, the [[circle of fifths]] is the same as that of [[7edo]], and every interval on the chain of fifths is [[neutral (interval quality)|neutral]] in quality. The whitewood temperament adds prime [[5/1|5]] as an independent [[generator]], adding subchromatically inflected intervals (notated with ups and downs below) on either side of the neutral ones.


The canonical [[extension]] to prime [[7/1|7]] adds [[36/35]] to the commas, thus equating [[5-limit]] major and minor intervals with [[7-limit]] subminor and supermajor ones. It finds [[7/4]] at the minor seventh, [[7/6]] at the minor third, and [[9/7]] at the major third.
The canonical [[extension]] to prime [[7/1|7]] adds [[36/35]] to the commas, thus equating [[5-limit]] major and minor intervals with [[7-limit]] subminor and supermajor ones. It finds [[7/4]] at the down seventh, [[7/6]] at the down third, and [[9/7]] at the up third.


For technical data, see [[Whitewood family #Whitewood]].
For technical data, see [[Whitewood family #Whitewood]].
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== Intervals ==
== Intervals ==
In the following table, odd harmonics and subharmonics 1–9 are in '''bold'''.
In the following table, odd harmonics and subharmonics 1–9 are in '''bold'''.
{| class="wikitable center-1 right-2 right-4 right-6 right-8"
{| class="wikitable center-1 right-2 right-4 right-6 right-8"
! rowspan="2" | Period
! rowspan="2" | Period
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== Tunings ==
== Tunings ==
Any multiple of [[7edo]], up until [[35edo]], contains 7edo's [[perfect fifth]], and thus supports whitewood, with all but 35edo supporting the canonical 7-limit extension by [[patent val]]. The most extreme tuning is [[14edo]], where major seconds and minor thirds are equated, and every interval is either a 7edo interval or halfway between two 7edo intervals. While the 14edo tuning approximates 5-limit intervals, it does approximate the [[6:7:9]] subminor and [[14:18:21|1/(9:7:6)]] supermajor triads fairly well. A less extreme tuning is [[21edo]], tuning [[7/4]] close to just and tuning [[5/4]] to the same 400{{C}} major third as in [[12edo]], though [[6/5]] is still about 30 cents flat. The [[28edo]] tuning has a near-just 5/4, and tunes whitewood about as best as it can be tuned.
Any multiple of [[7edo]], up until [[35edo]], contains 7edo's [[perfect fifth]], and thus supports whitewood, with all but 35edo supporting the canonical 7-limit extension by [[patent val]]. The most extreme tuning is [[14edo]], where up seconds and down thirds are equated, and every interval is either a 7edo interval or halfway between two 7edo intervals. While the 14edo tuning poorly approximates 5-limit intervals, it does approximate the [[6:7:9]] subminor and [[14:18:21|1/(9:7:6)]] supermajor triads fairly well. A less extreme tuning is [[21edo]], tuning [[7/4]] close to just and tuning [[5/4]] to the same 400{{c}} major third as in [[12edo]], though [[6/5]] is still about 30 cents flat. The [[28edo]] tuning has a near-just 5/4, and tunes whitewood about as best as it can be tuned.


=== Norm-based tunings ===
=== Norm-based tunings ===

Revision as of 08:39, 30 April 2026

Whitewood
Subgroups 2.3.5, 2.3.5.7
Comma basis 2187/2048 (2.3.5);
36/35, 2187/2048 (2.3.5.7)
Reduced mapping ⟨7; 0 1 -1]
ET join 7 & 14
Generators (CWE) ~5/4 = 392.7 ¢
MOS scales 7L 7s, 7L 14s, …
Ploidacot heptaploid acot
Pergen (P8/7, ^1)
Color name Lawati
Minimax error 5-odd-limit: 16.2 ¢;
9-odd-limit: 40.6 ¢
Target scale size 5-odd-limit: 14 notes;
9-odd-limit: 21 notes

Whitewood is the rank-2 temperament tempering out 2187/2048, the Pythagorean chromatic semitone. As a result, the circle of fifths is the same as that of 7edo, and every interval on the chain of fifths is neutral in quality. The whitewood temperament adds prime 5 as an independent generator, adding subchromatically inflected intervals (notated with ups and downs below) on either side of the neutral ones.

The canonical extension to prime 7 adds 36/35 to the commas, thus equating 5-limit major and minor intervals with 7-limit subminor and supermajor ones. It finds 7/4 at the down seventh, 7/6 at the down third, and 9/7 at the up third.

For technical data, see Whitewood family #Whitewood.

Intervals

In the following table, odd harmonics and subharmonics 1–9 are in bold.

Period Generator -1 Generator 0 Generator 1
Cents* Approx. ratios Cents* Approx. ratios Cents* Approx. ratios
0 0.0 1/1 49.9 64/63, 135/128
1 121.5 16/15, 28/27 171.4 9/8, 35/32 221.3 8/7, 10/9
2 293.0 6/5, 7/6 342.9 32/27, 81/64, 128/105 392.7 5/4
3 464.4 21/16 514.3 4/3 564.2 45/32
4 635.8 64/45 685.7 3/2 735.6 32/21
5 807.3 8/5, 14/9 857.1 27/16, 128/81, 105/64 907.0 5/3, 12/7
6 978.7 7/4, 9/5 1028.6 16/9, 64/35 1078.5 15/8, 27/14
7 1150.1 63/32, 256/135 1200.0 2/1

*in 7-limit CWE tuning

Tunings

Any multiple of 7edo, up until 35edo, contains 7edo's perfect fifth, and thus supports whitewood, with all but 35edo supporting the canonical 7-limit extension by patent val. The most extreme tuning is 14edo, where up seconds and down thirds are equated, and every interval is either a 7edo interval or halfway between two 7edo intervals. While the 14edo tuning poorly approximates 5-limit intervals, it does approximate the 6:7:9 subminor and 1/(9:7:6) supermajor triads fairly well. A less extreme tuning is 21edo, tuning 7/4 close to just and tuning 5/4 to the same 400 ¢ major third as in 12edo, though 6/5 is still about 30 cents flat. The 28edo tuning has a near-just 5/4, and tunes whitewood about as best as it can be tuned.

Norm-based tunings

5-limit norm-based tunings
Euclidean
Constrained Constrained & skewed Destretched
Tenney CTE: ~5/4 = 386.314 ¢ CWE: ~5/4 = 376.383 ¢ POTE: ~5/4 = 374.469 ¢
7-limit norm-based tunings
Euclidean
Constrained Constrained & skewed Destretched
Tenney CTE: ~5/4 = 392.930 ¢ CWE: ~5/4 = 392.741 ¢ POTE: ~5/4 = 392.699 ¢

Target tunings

Odd-limit-based target tunings
Target Minimax
Generator Eigenmonzo*
5-odd-limit ~5/4 = 378.193 ¢ 25/24
7-odd-limit ~5/4 = 394.458 ¢ 7/5
9-odd-limit ~5/4 = 394.458 ¢ 7/5

Tuning spectrum

Edo
generator
Unchanged interval
(eigenmonzo)
*
Generator (¢) Comments
2\7 342.857 Lower bound of 5-odd-limit diamond monotone
9/5 353.832
6/5 370.073
11\35 377.143 35d val
25/24 378.193 5-odd-limit minimax
9\28 385.714 Lower bound of 7-odd-limit diamond monotone
5/4 386.314
21/20 386.338
21/16 386.362
7/5 394.458 7- and 9-odd-limit minimax
7\21 400.000
15/8 402.554
15/14 402.579
7/4 402.603
49/48 410.723
7/6 418.843
5\14 428.571 Upper bound of 7-odd-limit diamond monotone
9/7 435.084
3\7 514.286 7cd val, Upper bound of 5-odd-limit diamond monotone

* Besides the octave