7edo: Difference between revisions

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It has often been stated that 7edo approximates tunings used in [[Thai]] classical music, though this is a myth unsupported by [[empirical]] studies of the instruments.<ref>Garzoli, John. [http://iftawm.org/journal/oldsite/articles/2015b/Garzoli_AAWM_Vol_4_2.pdf ''The Myth of Equidistance in Thai Tuning.'']</ref>
It has often been stated that 7edo approximates tunings used in [[Thai]] classical music, though this is a myth unsupported by [[empirical]] studies of the instruments.<ref>Garzoli, John. [http://iftawm.org/journal/oldsite/articles/2015b/Garzoli_AAWM_Vol_4_2.pdf ''The Myth of Equidistance in Thai Tuning.'']</ref>
=== Octave stretch ===
[[Stretched and compressed tuning|Stretched-octaves]] tunings such as [[11edt]], [[18ed6]] or [[Ed257/128 #7ed257/128|7ed257/128]] greatly improves 7edo's approximation of harmonics 3, 5 and 11, at the cost of slightly worsening 2 and 7, and greatly worsening 13. If one is hoping to use 7edo for [[11-limit]] harmonies, then these are good choices to make that easier.
The stretched 7edo tuning [[zpi|15zpi]] can also be used to improve 7edo's approximation of JI in a similar way.


=== Subsets and supersets ===
=== Subsets and supersets ===
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== Approximation to JI ==
== Approximation to JI ==
[[File:7ed2-001.svg|alt=alt : Your browser has no SVG support.]]
[[File:7ed2-001.svg]]
 
[[:File:7ed2-001.svg|7ed2-001.svg]]
 
=== Zeta peak index ===
{{ZPI
| zpi = 15
| steps = 6.95668765658792
| step size = 172.495885863671
| tempered height = 4.166936
| pure height = 3.940993
| integral = 1.162332
| gap = 14.234171
| octave = 1207.47120104570
| consistent = 6
| distinct = 5
}}


== Regular temperament properties ==
== Regular temperament properties ==
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3/7 is on the intersection of [[meantone]] and [[mavila]], and has MOS's of 331 and 21211, making 7edo the first edo with a non-equalized, non-1L''n''s [[pentatonic]] mos. This is in part because 7edo is close to low-complexity JI for its size, and is the second edo with a good fifth for its size (after [[5edo]]), the fifth serving as a generator for the edo's meantone and mavila interpertations.
3/7 is on the intersection of [[meantone]] and [[mavila]], and has MOS's of 331 and 21211, making 7edo the first edo with a non-equalized, non-1L''n''s [[pentatonic]] mos. This is in part because 7edo is close to low-complexity JI for its size, and is the second edo with a good fifth for its size (after [[5edo]]), the fifth serving as a generator for the edo's meantone and mavila interpertations.
== Octave stretch or compression ==
[[Stretched and compressed tuning|Stretched-octaves]] tunings such as [[11edt]], [[18ed6]] or [[zpi|15zpi]] greatly improves 7edo's approximation of harmonics 3, 5 and 11, at the cost of slightly worsening 2 and 7, and greatly worsening 13. If one is hoping to use 7edo for full [[11-limit]] harmonies, then these are good choices to make that easier.


== Instruments ==
== Instruments ==
* [[Lumatone mapping for 7edo]]
* [[Lumatone mapping for 7edo]]
In addition, various fretted string instruments have been built to play in 7edo (an example is linked in the [[#see also]] section below).


== Music ==
== Music ==
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== Ear training ==
== Ear training ==
7edo ear-training exercises by Alex Ness available [https://drive.google.com/folderview?id=0BwsXD8q2VCYUT3VEZUVmeVZUcmc&usp=drive_web#list here].
7edo ear-training exercises by Alex Ness available [https://drive.google.com/folderview?id=0BwsXD8q2VCYUT3VEZUVmeVZUcmc&usp=drive_web#list here].
== See also ==
* [[Alpha, beta, and gamma family of equal divisions]]
; [[Noah Jordan]]
* [https://www.youtube.com/watch?v=6MDUxUEnQT4 ''7 tone equal temperament (7edo) microtonal tuning talk and demonstration''] (2024) — Here, Noah Jordan uses variations in the tuning of a {{W|jarana jarocha}} fretted for 7edo to demonstrate the concept of modifying a 7edo tuning to get non-neutral pitches.


== Notes ==
== Notes ==