User:Lhearne/15edo: Difference between revisions

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==Introduction==
==Introduction==
15 Equal Divisions of the Octave (15edo) is a tuning which divides the octave into 15 equally spaced pitches. It can be thought of as three sets of 5edo connected to each other by intervals of 3edo.
15 Equal Divisions of the Octave (15edo) is a tuning which divides the octave into 15 equally spaced pitches. It can be thought of as three sets of 5edo connected to each other by intervals of 3edo.
[[category:alternative pages]]


From [http://en.wikipedia.org/wiki/15_equal_temperament Wikipedia]:
From [http://en.wikipedia.org/wiki/15_equal_temperament Wikipedia]:
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|<15 24 35 52]
|<15 24 35 52]
|14.693746
|14.693746
|-
|2.3.7.11
|<15 24 42 52]
|18.660367
|-
|-
|2.5.7.11
|2.5.7.11
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|}
|}


The following table, revealing a close approximation of 13/9, effectively treats 15edo as a 2.3.5.7.13/9 subgroup temperament. It's handy because of it's visual-ness.
The following diagram shows how closely some prominent JI intervals are approximated in 15edo, using their best direct mappings, even if they lead to inconsistencies.


[[File:15ed2-001.svg|border|link=https://en.xen.wiki/w/File:15ed2-001.svg]]
[[File:15ed2-001.svg|border|link=https://en.xen.wiki/w/File:15ed2-001.svg]]
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|48.298
|48.298
|}
|}
=Rank two temperaments=
=Rank two temperaments=
[[List of 15et rank two temperaments by badness]]
[[List of 15et rank two temperaments by badness]]
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Blackwood[10]: 2121212121 (Blackwood Decatonic)
Blackwood[10]: 2121212121 (Blackwood Decatonic)
Augmented[12]: 211121112111


=== Other Scales ===
=== Other Scales ===
Zarlino/Ptolemy JI Major: 3213231
Zarlino/Ptolemy diatonic, "just" major, Ma grama - 3213231
 
inverse of Zarlino/Ptolemy diatonic, natural minor - 3123132
 
tetrachordal major, Sa grama - 3213321
 
inverse of tetrachordal major, "just"/tetrachordal minor - 3123123
 
Porcupine bright major #7 - Porcupine[7] 6|0 #7 - 3222231
 
Porcupine bright major #6 #7 - Porcupine[7] 6|0 #7 - 3222321
 
Porcupine bright minor #2 - Porcupine[7] 4|2 #2 3132222 (mode of bright major #7)
 
Porcupine dark minor #2 - Porcupine[7] 3|3 #2 3123222 (inverse of bright major #6 #7)
 
Porcupine bright harmonic 11th mode - Porcupine[7] 6|0 b7 3222213
 
"just" harmonic minor - 3123141
 
"just" harmonic major - 3213141
 
"just" melodic minor ascending - 3123231
 
"just" double harmonic - 1413141


=Notation=
=Notation=
Because 15edo's best fifth is the same as that of [[5edo]], the circle of fifths fully closes with only five notes, meaning the [[256/243|Pythagorean limma]] is tempered out.  This slightly breaks traditional fifth-based notation, because E and F, as well as B and C, will merge into singular pitches.  This also has the effect of making the [[2187/2048|Pythagorean apotome]] equal to the [[9/8|Pythagorean whole-tone]], such that the sharp and flat accidentals will indicate raising or lowering by one step of 5edo, or 240 cents.  There are two main approaches to dealing with this issue: the use of ups and downs in conjunction with the traditional A through G nominals based on the 5edo circle of fifths, and the use of Porcupine temperament instead of the circle of fifths as a notational basis.
Because 15edo's best fifth is the same as that of [[5edo]], the circle of fifths fully closes with only five notes, meaning the [[256/243|Pythagorean limma]] is tempered out.  This slightly breaks traditional fifth-based notation, because E and F, as well as B and C, will merge into singular pitches.  This also has the effect of making the [[2187/2048|Pythagorean apotome]] equal to the [[9/8|Pythagorean whole-tone]], such that the sharp and flat accidentals will indicate raising or lowering by one step of 5edo, or 240 cents.  There are two main approaches to dealing with this issue: the use of ups and downs in conjunction with the traditional A through G nominals based on the 5edo circle of fifths, and the use of Porcupine temperament instead of the circle of fifths as a notational basis.
==Ups and Downs Notation==
==Ups and downs notation==
In [[Ups and Downs Notation#Summary of EDO notation-.22Pentatonic.22 EDOs|ups and downs notation]], which is fifth-generated, every 15edo note has at least three names.
In [[Ups and downs notation#Summary of EDO notation-.22Pentatonic.22 EDOs|ups and downs notation]], which is fifth-generated, every 15edo note has at least three names.
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0-4-9-13 = D F^ A C^ = D.^m7 = "D dot up minor-seven", or D F^ A B^ = D.^m6 = "D dot up minor-six"
0-4-9-13 = D F^ A C^ = D.^m7 = "D dot up minor-seven", or D F^ A B^ = D.^m6 = "D dot up minor-six"


For a more complete list, see [[Ups and Downs Notation#Chord names in other EDOs|Ups and Downs Notation - Chord names in other EDOs]].
For a more complete list, see [[Ups and downs notation#Chord names in other EDOs|Ups and downs notation - Chord names in other EDOs]].
==Porcupine[7] Notation==
==Porcupine[7] Notation==
''See the main [[Porcupine Notation|porcupine notation]] page.''
''See the main [[Porcupine Notation|porcupine notation]] page.''


15edo can also be notated using the [[Ups and Downs Notation#Natural Generators|natural generator]], which is not the 9\15 5th but the 2\15 2nd. For 15edo, this is also known as porcupine notation. The 15edo porcupine genchain in both relative and absolute notation:
15edo can also be notated using the [[Ups and downs notation#Natural Generators|natural generator]], which is not the 9\15 5th but the 2\15 2nd. For 15edo, this is also known as porcupine notation. The 15edo porcupine genchain in both relative and absolute notation:


...A3 - A4 - A5 - A6 - A7 - A1 - A2 - M3 - M4 - M5 - M6 - P7 - P1 - P2 - m3 - m4 - m5 - m6 - d7 -- d8 - d2 - d3 -- d4 - d5 -- d6...
...A3 - A4 - A5 - A6 - A7 - A1 - A2 - M3 - M4 - M5 - M6 - P7 - P1 - P2 - m3 - m4 - m5 - m6 - d7 -- d8 - d2 - d3 -- d4 - d5 -- d6...
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| style="text-align: center;" data-ve-style="text-align:center;" data-ve-attributes="{&quot;style&quot;:&quot;text-align: center;&quot;}" |do
| style="text-align: center;" data-ve-style="text-align:center;" data-ve-attributes="{&quot;style&quot;:&quot;text-align: center;&quot;}" |do
|}
|}
==Porcupine[8] Notation:==
==Porcupine[8] Notation==
An alternative porcupine notation is based on the porcupine[8] LLLLLLLs scale using eight nominals α β χ δ ε φ γ η. Others have proposed ABCDEFGHA, but conflicts with European notation have caused many to reject this approach. Thus greek letters can be used in place with a close resemblance to the spelling of ABCDEFGHA.
An alternative porcupine notation is based on the porcupine[8] LLLLLLLs scale using eight nominals α β χ δ ε φ γ η. Others have proposed ABCDEFGHA, but conflicts with European notation have caused many to reject this approach. Thus greek letters can be used in place with a close resemblance to the spelling of ABCDEFGHA.
{| class="wikitable"
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=Theory=
=Theory=
[http://sonic-arts.org/darreg/dar35.htm The 15-Tone Scale System] by [[Ivor Darreg]] [http://www.webcitation.org/5xZyzKBEW Permalink]
[http://www.webcitation.org/5xZyzKBEW The 15-Tone Scale System] by [[Ivor_Darreg|Ivor Darreg]] (Originally at [http://sonic-arts.org/darreg/dar35.htm], now broken)
 
[https://web.archive.org/web/20110713044141/http://www.inteas.com/Penta01.htm The Pentadecaphonic System] (Originally at [http://www.inteas.com/Penta01.htm], now broken)


[http://www.inteas.com/Penta01.htm The Pentadecaphonic System]
[http://www.webcitation.org/5xeJYBsDg 15-EDO Tutorial] by [[Brent_Carson|Brent Carson]] (Originally at [http://home.comcast.net/%7Ebrentishere/15noteequaltempermenttutorial.html], now broken)


[http://home.comcast.net/~brentishere/15noteequaltempermenttutorial.html 15-EDO Tutorial] by [[Brent Carson]] [http://www.webcitation.org/5xeJYBsDg Permalink]
=Practical Theory / Books=
=Practical Theory / Books=
[http://www.swordguitars.com/ Sword, Ronald. "Pendecaphonic Scales for Guitar" IAAA Press, UK-USA. First Ed: June 2009.] - A large repository of all known scales and temperament families in the 15-edo system. 300+ examples /w chord-scale progressions.
[http://www.swordguitars.com/ Sword, Ronald. "Pendecaphonic Scales for Guitar" IAAA Press, UK-USA. First Ed: June 2009.] - A large repository of all known scales and temperament families in the 15-edo system. 300+ examples /w chord-scale progressions.