View source for Chain-of-fifths notation

The '''circle-of-fifths notation''' (aka '''extended Pythagorean notation''') is suitable to open up the variety of tones of a selection of [[edo]]s and [[regular temperament]]s of fifth generator. The principle is based on one of the intervals taking over the role of the fifth of the traditional classical notation system (in [[12edo]] or the [[meantone]] tuning). The classical notation system uses seven root notes and accidentals (<span style="font-size:larger">♯, ♭</span> and their multiples) to sharpen and flatten these root notes by the same amount (which is an octave-reduced stack of 7 fifths). 

Edos that are best supported by this system are those whose fifth does not deviate too much from the pure fifth [[3/2]] (702{{cent}}) and that can be represented by only one ring of fifths. [[24edo]], as a counter-example to this, contains two rings. If we as well demand that whole tones (2 × P5 - P8), diatonic semitones (3 × P8 - 5 × P5), and chromatic semitones (shifts caused by one accidental, 7 × P5 - 4 × P8), use a positive number of steps, we exclude all edos below 12 and also {{EDOs| 13, 16, 18, and 23 }}. They make more sense notated as subsets. For example, 13edo can be notated as a subset of [[26edo]]. 

The '''neutral circle-of-fifths notation''' (aka '''quartertone notation''') uses an extended accidental set including '''demisharps''' and '''demiflats'''. It works for any tuning system generated by a neutral third. The [[mohaha]] temperament and its typical edo tunings ([[17edo]], 24edo, [[31edo]], [[38edo]], [[45edo]]) are well represented by this system. 

== Edos up to 100 ==
Edos up to 100 are listed in the following tables. The unit (if not stated otherwise) is ''steps'' of the corresponding edo which is given in the first column of each row. The list contains only those edos whose all degrees can be reached by stacking the [[direct approximation]] of the fifth in the respective edo.

{| class="wikitable center-all"
|-
|+ Edos fit for circle-of-fifths notation
|-
! Edo
! Fifth
! Fifth-detuning <br> abs(¢), rel(%)
! Whole<br>tone
! Diatonic<br>semitone
! Chromatic<br>semitone
|-
! [[12edo|12]]
|  7 ||  -2.0 ( -2.0%) ||  2 ||  1 ||  1
|-
! [[17edo|17]]
| 10 ||  +3.9 ( +5.6%) ||  3 ||  1 ||  2
|-
! [[19edo|19]]
| 11 ||  -7.2 (-11.4%) ||  3 ||  2 ||  1
|-
! [[22edo|22]]
| 13 ||  +7.1 (+13.1%) ||  4 ||  1 ||  3
|-
! [[26edo|26]]
| 15 ||  -9.6 (-20.9%) ||  4 ||  3 ||  1
|-
! [[27edo|27]]
| 16 ||  +9.2 (+20.6%) ||  5 ||  1 ||  4
|-
! [[29edo|29]]
| 17 ||  +1.5 ( +3.6%) ||  5 ||  2 ||  3
|-
! [[31edo|31]]
| 18 ||  -5.2 (-13.4%) ||  5 ||  3 ||  2
|-
! [[32edo|32]]
| 19 || +10.5 (+28.1%) ||  6 ||  1 ||  5
|-
! [[33edo|33]]
| 19 || -11.0 (-30.4%) ||  5 ||  4 ||  1
|-
! [[37edo|37]]
| 22 || +11.6 (+35.6%) ||  7 ||  1 ||  6
|-
! [[39edo|39]]
| 23 ||  +5.7 (+18.6%) ||  7 ||  2 ||  5
|-
! [[40edo|40]]
| 23 || -12.0 (-39.9%) ||  6 ||  5 ||  1
|-
! [[41edo|41]]
| 24 ||  +0.5 ( +1.7%) ||  7 ||  3 ||  4
|-
! [[42edo|42]]
| 25 || +12.3 (+43.2%) ||  8 ||  1 ||  7
|-
! [[43edo|43]]
| 25 ||  -4.3 (-15.3%) ||  7 ||  4 ||  3
|-
! [[45edo|45]]
| 26 ||  -8.6 (-32.3%) ||  7 ||  5 ||  2
|-
! [[46edo|46]]
| 27 ||  +2.4 ( +9.2%) ||  8 ||  3 ||  5
|-
! [[47edo|47]]
| 27 || -12.6 (-49.3%) ||  7 ||  6 ||  1
|-
! [[49edo|49]]
| 29 ||  +8.2 (+33.7%) ||  9 ||  2 ||  7
|-
! [[50edo|50]]
| 29 ||  -6.0 (-24.8%) ||  8 ||  5 ||  3
|-
! [[53edo|53]]
| 31 ||  -0.1 ( -0.3%) ||  9 ||  4 ||  5
|-
! [[55edo|55]]
| 32 ||  -3.8 (-17.3%) ||  9 ||  5 ||  4
|-
! [[56edo|56]]
| 33 ||  +5.2 (+24.2%) || 10 ||  3 ||  7
|-
! [[59edo|59]]
| 35 ||  +9.9 (+48.7%) || 11 ||  2 ||  9
|-
! [[61edo|61]]
| 36 ||  +6.2 (+31.7%) || 11 ||  3 ||  8
|-
! [[63edo|63]]
| 37 ||  +2.8 (+14.7%) || 11 ||  4 ||  7
|-
! [[64edo|64]]
| 37 ||  -8.2 (-43.8%) || 10 ||  7 ||  3
|-
! [[65edo|65]]
| 38 ||  -0.4 ( -2.3%) || 11 ||  5 ||  6
|-
! [[67edo|67]]
| 39 ||  -3.4 (-19.2%) || 11 ||  6 ||  5
|-
! [[69edo|69]]
| 40 ||  -6.3 (-36.2%) || 11 ||  7 ||  4
|-
! [[70edo|70]]
| 41 ||  +0.9 ( +5.3%) || 12 ||  5 ||  7
|-
! [[71edo|71]]
| 42 ||  +7.9 (+46.8%) || 13 ||  3 || 10
|-
! [[73edo|73]]
| 43 ||  +4.9 (+29.8%) || 13 ||  4 ||  9
|-
! [[74edo|74]]
| 43 ||  -4.7 (-28.7%) || 12 ||  7 ||  5
|-
! [[75edo|75]]
| 44 ||  +2.0 (+12.8%) || 13 ||  5 ||  8
|-
! [[77edo|77]]
| 45 ||  -0.7 ( -4.2%) || 13 ||  6 ||  7
|-
! [[79edo|79]]
| 46 ||  -3.2 (-21.2%) || 13 ||  7 ||  6
|-
! [[80edo|80]]
| 47 ||  +3.0 (+20.3%) || 14 ||  5 ||  9
|-
! [[81edo|81]]
| 47 ||  -5.7 (-38.2%) || 13 ||  8 ||  5
|-
! [[83edo|83]]
| 49 ||  +6.5 (+44.8%) || 15 ||  4 || 11
|-
! [[88edo|88]]
| 51 ||  -6.5 (-47.7%) || 14 ||  9 ||  5
|-
! [[89edo|89]]
| 52 ||  -0.8 ( -6.2%) || 15 ||  7 ||  8
|-
! [[90edo|90]]
| 53 ||  +4.7 (+35.3%) || 16 ||  5 || 11
|-
! [[91edo|91]]
| 53 ||  -3.1 (-23.2%) || 15 ||  8 ||  7
|-
! [[94edo|94]]
| 55 ||  +0.2 ( +1.4%) || 16 ||  7 ||  9
|-
! [[95edo|95]]
| 56 ||  +5.4 (+42.9%) || 17 ||  5 || 12
|-
! [[97edo|97]]
| 57 ||  +3.2 (+25.9%) || 17 ||  6 || 11
|-
! [[98edo|98]]
| 57 ||  -4.0 (-32.6%) || 16 ||  9 ||  7
|-
! [[99edo|99]]
| 58 ||  +1.1 ( +8.9%) || 17 ||  7 || 10
|}

{| class="wikitable center-all"
|-
|+ Edos fit for neutral circle-of-fifths notation
|-
! Edo
! Fifth
! Fifth-detuning <br> abs(¢), rel(%)
! Whole<br>tone
! Diatonic<br>semitone
! Chromatic<br>semitone
|-
! [[17edo|17]]
| 10 ||  +3.9 ( +5.6%) ||  3 ||  1 ||  2
|-
! [[24edo|24]]
| 14 ||  -4.0 (-4.0%) ||  4 ||  2 ||  2
|-
! [[27edo|27]]
| 16 ||  +9.2 (+20.6%) ||  5 ||  1 ||  4
|-
! [[31edo|31]]
| 18 ||  -5.2 (-13.4%) ||  5 ||  3 ||  2
|-
! [[37edo|37]]
| 22 || +11.6 (+35.6%) ||  7 ||  1 ||  6
|-
! [[38edo|38]]
| 22 || -7.2 (-22.9%) ||  6 ||  4 ||  2
|-
! [[41edo|41]]
| 24 ||  +0.5 ( +1.7%) ||  7 ||  3 ||  4
|-
! [[44edo|44]]
| 26 ||  +7.1 (+26.2%) ||  8 ||  2 ||  6
|-
! [[45edo|45]]
| 26 ||  -8.6 (-32.3%) ||  7 ||  5 ||  2
|-
! [[52edo|52]]
| 30 ||  -9.6 (-41.8%) ||  8 ||  6 ||  2
|-
! [[55edo|55]]
| 32 ||  -3.8 (-17.3%) ||  9 ||  5 ||  4
|-
! [[58edo|58]]
| 34 ||  +1.5 ( +3.6%) || 10 ||  4 ||  6
|-
! [[61edo|61]]
| 36 ||  +6.2 (+31.7%) || 11 ||  3 ||  8
|-
! [[65edo|65]]
| 38 ||  -0.4 ( -2.3%) || 11 ||  5 ||  6
|-
! [[69edo|69]]
| 40 ||  -6.3 (-36.2%) || 11 ||  7 ||  4
|-
! [[71edo|71]]
| 42 ||  +7.9 (+46.8%) || 13 ||  3 || 10
|-
! [[75edo|75]]
| 44 ||  +2.0 (+12.8%) || 13 ||  5 ||  8
|-
! [[78edo|78]]
| 46 ||  +5.7 (+37.3%) || 14 ||  4 || 10
|-
! [[79edo|79]]
| 46 ||  -3.2 (-21.2%) || 13 ||  7 ||  6
|-
! [[86edo|86]]
| 50 ||  -4.3 (-30.7%) || 14 ||  8 ||  6
|-
! [[89edo|89]]
| 52 ||  -0.8 ( -6.2%) || 15 ||  7 ||  8
|-
! [[92edo|92]]
| 54 ||  +2.4 ( +18.3%) || 16 ||  6 || 10
|-
! [[95edo|95]]
| 56 ||  +5.4 (+42.9%) || 17 ||  5 || 12
|-
! [[99edo|99]]
| 58 ||  +1.1 ( +8.9%) || 17 ||  7 || 10
|}

== Expansions ==
* [[Syntonic-rastmic subchroma notation]] – built on neutral circle-of-fifths notation
* [[Ups and downs notation]] – built on circle-of-fifths notation
** Neutral ups and downs notation (→ [[Alternative symbols for ups and downs notation]])
* [[Sagittal notation]] (''evo flavor'') – built on circle-of-fifths notation or neutral circle-of-fifths notation

== See also ==
* [[Nominal-accidental chain]]
* [[Circle of fifths]]
* [[Fifthspan]]
* [[User:Xenwolf/cofn]] – sortable table with more intervals (all fifths within the interval [4\7, 3\5], the "[[diatonic range]]")

[[Category:Notation]]
[[Category:Method]]
[[Category:Fifth]]