Whitewood

Revision as of 22:03, 28 April 2026 by Overthink (talk | contribs) (mention 7edo; link)

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 major and minor intervals on either side of the neutral ones.

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

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 minor seventh, 7/6 at the minor third, and 9/7 at the major 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, 128/81 907.0 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

  Todo: complete section