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
- 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
| 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