rationalizing the natural scale

Here again is the table of the frequencies of the steps in the natural scale and the gaps between them, both expressed as binary logarithms:

step log(2) of freq difference, in log(2), between steps
1 1
0.093
7 0.907
0.17
6 0.737
0.152
5 0.585
0.17
4 0.415
0.093
3 0.322
0.152
2 0.17
0.17
1 0

Here's how that looks as a 1-dimensional graph:

1        2          3    4        5         6         7    1    steps in log(2)
0    .1    .2    .3    .4    .5    .6    .7    .8    .9    1.0  log(2)
  • note that the gaps can be put into two categories:
    • 1. ~ 0.16
    • 2. 0.093
  • note that the category 1 gaps are roughly half the size of those in category 2
    • this suggests that we could insert a new step in the category 1 gaps, halfway between the two frequencies in each gap, thereby creating 12 roughly equidistant steps
      0    .1    .2    .3    .4    .5    .6    .7    .8    .9    1.0  scale in log(2)
      1   .    2    .     3    4   .    5    .    6    .    7    1  steps in log(2)
      

      (. = new step)

    • 7 of these 12 steps have the same pitch as a natural scale step
1 2 3 4 5 6 7 8 9 10 11 12 1 12-step scale
1 2 3 4 5 6 7 1 natural scale
2 2 1 2 2 2 1 gaps
  • note that the gap unit is one 12-step scale step

  • note the pattern of the gaps: 2, 2, 1, 2, 2, 2, 1