EDe: Difference between revisions
Reword intro, replace EDN instances w EDe |
|||
| Line 1: | Line 1: | ||
{{Mathematical interest}} | {{Mathematical interest}} | ||
Equal | '''Equal division of the [[natave]]''' ('''EDe''' or '''EDN''') is the equal division of the constant ''e'' (where ''e'' is treated as a musical interval in the same way as ''2'' is an octave or ''1.5'' is a perfect fifth). | ||
== Correspondence of | ''e'' is of particular interest because of its relationship with logarithms, given the fact that pitch is perceived logarithmically, and the fact that equal divisions are logarithmic. | ||
== Correspondence of EDe to EDO == | |||
{| class="wikitable" | {| class="wikitable" | ||
|- | |- | ||
| Line 10: | Line 12: | ||
! Comment | ! Comment | ||
|- | |- | ||
| | | 2EDe | ||
| | | | ||
| A stack of two major sixths | | A stack of two major sixths | ||
|- | |- | ||
| | | 3EDe | ||
| [[2edo]] | | [[2edo]] | ||
| | | | ||
|- | |- | ||
| | | 4EDe | ||
| | | | ||
| rowspan="2" |Neither are equivalent with [[3edo]] | | rowspan="2" |Neither are equivalent with [[3edo]] | ||
|- | |- | ||
| | | 5EDe | ||
| | | | ||
|- | |- | ||
| | | 6EDe | ||
| [[4edo]] | | [[4edo]] | ||
| With a stretch | | With a stretch | ||
|- | |- | ||
| | | 7EDe | ||
| [[5edo]] | | [[5edo]] | ||
| | | | ||
|- | |- | ||
| | | 8EDe | ||
| | | | ||
| Entirely misses 2/1, falling halfway between 5edo and 6edo | | Entirely misses 2/1, falling halfway between 5edo and 6edo | ||
|- | |- | ||
| | | 9EDe | ||
| [[6edo]] | | [[6edo]] | ||
| With a considerable stretch | | With a considerable stretch | ||
|- | |- | ||
| | | 10EDe | ||
| [[7edo]] | | [[7edo]] | ||
| | | | ||
|- | |- | ||
| | | 11EDe | ||
| | | | ||
| rowspan="2" |Neither are equivalent to 8edo | | rowspan="2" |Neither are equivalent to 8edo | ||
|- | |- | ||
| | | 12EDe | ||
| | | | ||
|- | |- | ||
| | | 13EDe | ||
| [[9edo]] | | [[9edo]] | ||
| | | | ||
|- | |- | ||
| | | 14EDe | ||
| | | | ||
| rowspan="2" |Neither are equivalent to 10edo | | rowspan="2" |Neither are equivalent to 10edo | ||
|- | |- | ||
| | | 15EDe | ||
| | | | ||
|- | |- | ||
| | | 16EDe | ||
| [[11edo]] | | [[11edo]] | ||
| | | | ||
|- | |- | ||
| | | 17EDe | ||
| [[12edo]] | | [[12edo]] | ||
| With a noticeable stretch, given the dominance of 12edo this is more likely to sound like out of tune 12edo than it's own tuning | | With a noticeable stretch, given the dominance of 12edo this is more likely to sound like out of tune 12edo than it's own tuning | ||
|- | |- | ||
| | | 18EDe | ||
| | | | ||
| Entirely misses 2/1, falling halfway between 12 and 13edo | | Entirely misses 2/1, falling halfway between 12 and 13edo | ||
|- | |- | ||
| | | 19EDe | ||
| [[13edo]] | | [[13edo]] | ||
| Noticeably compressed | | Noticeably compressed | ||
|- | |- | ||
| | | 20EDe | ||
| [[14edo]] | | [[14edo]] | ||
| Noticeably stretched | | Noticeably stretched | ||
|- | |- | ||
| | | 21EDe | ||
| | | | ||
| Entirely misses 2/1, falling halfway between 14edo and 15edo | | Entirely misses 2/1, falling halfway between 14edo and 15edo | ||
|- | |- | ||
| | | 22EDe | ||
| | | | ||
| Cannot be considered equivalent to [[15edo]] | | Cannot be considered equivalent to [[15edo]] | ||
|- | |- | ||
| | | 23EDe | ||
| [[16edo]] | | [[16edo]] | ||
| | | | ||
|- | |- | ||
| | | 24EDe | ||
| [[17edo]] | | [[17edo]] | ||
| Some equivalences can be spotted due to 17edo's fame but it's a heavy stretch amounting to 40% | | Some equivalences can be spotted due to 17edo's fame but it's a heavy stretch amounting to 40% | ||
| Line 103: | Line 105: | ||
In [[Gene Ward Smith|Gene]]’s [[the Riemann zeta function and tuning#The Black Magic Formulas|black magic formulas]], it is mathematically more "natural" to consider the number of divisions to the natave rather than the octave, thus scaling the graph of |''Z''(''x'')| horizontally by a factor of 1 instead of 1/ln(2). | In [[Gene Ward Smith|Gene]]’s [[the Riemann zeta function and tuning#The Black Magic Formulas|black magic formulas]], it is mathematically more "natural" to consider the number of divisions to the natave rather than the octave, thus scaling the graph of |''Z''(''x'')| horizontally by a factor of 1 instead of 1/ln(2). | ||
The sequence of non-[[stretched and compressed tuning|stretched]] zeta peak | The sequence of non-[[stretched and compressed tuning|stretched]] zeta peak EDe's are 1, 2, 3, 10, 20, 36, 39, 72, 111, 163, 202, 264, 466, 538, 740, 1349, 1887... corresponding to {{EDOs|1, 1, 2, 7, 14, 25, 27, 50, 77, 113, 140, 183, 323, 373, 513, 935, 1308}}... edos. | ||
== Selected divisions == | == Selected divisions == | ||
=== 10- | === 10-EDe === | ||
{| class="wikitable" | {| class="wikitable" | ||
|+ style="font-size: 105%;" | Intervals of 10-EDN | |+ style="font-size: 105%;" | Intervals of 10-EDN | ||
| Line 185: | Line 187: | ||
Beyond the natave, some particularly pleasant JI intervals can be found: 11\10 is only 2 cents sharp from 3/1; 13\10 is very close to 11/2; and 23\10 is very close to 10/1. This last approximation in particular makes this equal division almost equivalent to 23-ed(10/1). | Beyond the natave, some particularly pleasant JI intervals can be found: 11\10 is only 2 cents sharp from 3/1; 13\10 is very close to 11/2; and 23\10 is very close to 10/1. This last approximation in particular makes this equal division almost equivalent to 23-ed(10/1). | ||
10- | 10-EDe is similar to 7-EDO in that its step size is roughly 1/7 of an octave, therefore roughly corresponding to the diatonic scale, but with warped, equal-size steps. However, the octave is stretched, which simultaneously helps the extremely flat fifth of 7-EDO. | ||
{{Harmonics in equal|10|1457|536|title=Approximation of harmonics in 10- | {{Harmonics in equal|10|1457|536|title=Approximation of harmonics in 10-EDe}} | ||
=== 17- | === 17-EDe === | ||
17-EDN is very close to 12-EDO but with slightly sharp semitones (101.84 cents). This causes the octave to be far too sharp (1222.05 cents; essentially double a Pythagorean large tritone) and gives it a rather pleasant sharp fifth of 712.86 cents. | 17-EDN is very close to 12-EDO but with slightly sharp semitones (101.84 cents). This causes the octave to be far too sharp (1222.05 cents; essentially double a Pythagorean large tritone) and gives it a rather pleasant sharp fifth of 712.86 cents. | ||
{{Harmonics in equal|17|1457|536|title=Approximation of harmonics in 17- | {{Harmonics in equal|17|1457|536|title=Approximation of harmonics in 17-EDe}} | ||
=== 20- | === 20-EDe === | ||
20- | 20-EDe is a doubling of 10-EDe with intervals closer to semitones. | ||
{{Harmonics in equal|20|1457|536|title=Approximation of harmonics in 20- | {{Harmonics in equal|20|1457|536|title=Approximation of harmonics in 20-EDe}} | ||
=== 24- | === 24-EDe === | ||
24- | 24-EDe has third tones so far sharp of 17-EDO that it becomes a stretched 50-ED8 (50\24 is 3606.74 cents). However, 43\24 is essentially the 6th harmonic (1514.83+1586.965=3101.79 cents). | ||
{{Harmonics in equal|24|1457|536|title=Approximation of harmonics in 24- | {{Harmonics in equal|24|1457|536|title=Approximation of harmonics in 24-EDe}} | ||
[[Category:Transcendental]] | [[Category:Transcendental]] | ||
[[Category:Equal-step tuning]] | [[Category:Equal-step tuning]] | ||