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{{Wikipedia}}
{{Infobox interval region|Name=Semitone, minor second, augmented unison|Cents lower=75|Cents lower wide=60|Cents upper=125|Cents upper wide=140|JI intervals=16/15, 25/24|MOSes=1L 8s, 9L 1s, 1L 9s|Complement=[[Major seventh]]|Lower region=[[Comma and diesis]]|Higher region=[[Neutral second]]}}{{Wikipedia|Semitone}}
{{About|the [[interval region]]|the interval size unit of exactly 100 cents|Interval size measure#Gross}}
A '''semitone''', as a concrete [[interval region]], is typically near 100{{cent}} in size, distinct from [[commas and dieses]] (less than 60{{c}}), and from [[neutral second]]s (about 150{{c}}). A rough tuning range for the semitone is about 60{{c}} to 125{{c}} according to [[Margo Schulter]]'s theory of interval regions.
A '''semitone''' is an interval that is near 100 [[cent]]s in size, distinct from [[Comma and diesis|commas and dieses]] (less than 60 cents), and from [[major second]]s (about 200 cents). A rough tuning range for the semitone is about 50 cents to 140 cents, though this is extremely wide; some might prefer to restrict it to around 70 cents to 130 cents.  
Functionally, a semitone is an interval that makes up part of a [[tone]], often as one step of a 12-tone chromatic scale, which is a possible criterion for the classification of an interval as a semitone in [[just intonation]].  


Semitones tend to fall into one of two functional categories, based on the system being used:  
Semitones come in two functional categories based on their number of steps in the [[5L 2s|diatonic]] scale:  
* [[diatonic semitone]]s, minor seconds (m2) or limmas,
*[[Diatonic semitone]]s, minor seconds (m2), or limmas,
* [[chromatic semitone]]s, augmented unisons (A1) or chromas.
*[[Chromatic semitone]]s, augmented unisons (A1), or chromas.


This page covers both categories of intervals, as the distinction between them is largely a matter of the [[diatonic]] MOS, and is also not the subject of this article.  
The intervals covered in this article range from 50{{c}} to 140{{c}}.  


== In just intonation ==
== In just intonation ==
=== By prime limit ===
=== By prime limit ===
In the low prime limits, up to the 5-limit, in which the West has developed a formal system of diatonic harmony, the distinction between diatonic and chromatic semitones is the clearest, so a pair of 2 semitones will be provided for each. However, higher than the 5-limit, function as diatonic vs. chromatic tends to become less clear, and larger intervals can be seen as belonging to neither category.
In the low prime limits, up to the 5-limit, in which the West has developed a formal system of diatonic harmony, the distinction between diatonic and chromatic semitones is the clearest, so a pair of 2 semitones will be provided for each. However, higher than the 5-limit, function as diatonic vs. chromatic tends to become less clear, and larger intervals can be seen as belonging to neither category.


* In the 3-limit:
* In the 3-limit:
** The '''limma,''' or Pythagorean diatonic semitone, is a ratio of 256/243, and is about 90 cents.
** The ''limma'', or ''Pythagorean diatonic semitone'', is a ratio of [[256/243]], and is about 90{{c}}.
** The '''apotome,''' or Pythagorean chromatic semitone, is a ratio of 2187/2048, and is about 114 cents.
** The ''apotome'', or ''Pythagorean chromatic semitone'', is a ratio of [[2187/2048]], and is about 114{{c}}.
* In the 5-limit:
* In the 5-limit:
** The '''classical diatonic semitone''' is a ratio of 16/15, and is about 112 cents.
** The ''classical diatonic semitone'' is a ratio of [[16/15]], and is about 112{{c}}.
** The '''classical chromatic semitone''' is a ratio of 25/24, and is about 71 cents.
** The ''classical chromatic semitone'' is a ratio of [[25/24]], and is about 71{{c}}.
*** There is also a '''ptolemaic chromatic semitone,''' which is a ratio of 135/128, and is about 92 cents.
*** There is also a ''ptolemaic chromatic semitone'', which is a ratio of [[135/128]], and is about 92{{c}}.
* In higher limits:
* In higher limits:
** The 7-limit '''third-tone''' is a ratio of 28/27, and is about 63 cents.
** The 7-limit ''third-tone'' is a ratio of [[28/27]], and is about 63{{c}}.
** The 7-limit '''minor semitone''' is a ratio of 21/20, and is about 84 cents.
** The 7-limit ''minor semitone'' is a ratio of [[21/20]], and is about 84{{c}}.
** The 7-limit '''major semitone''' is a ratio of 15/14, and is about 119 cents.
** The 7-limit ''major semitone'' is a ratio of [[15/14]], and is about 119{{c}}.
** The 11-limit '''minor semitone''' is a ratio of 22/21, and is about 81 cents.
** The 11-limit ''minor semitone'' is a ratio of [[22/21]], and is about 81{{c}}.
** The 13-limit '''sinaic''' is a ratio of 14/13, and is about 128 cents.
** The 13-limit ''sinaic'' is a ratio of [[14/13]], and is about 128{{c}}.
** The 13-limit '''greater 2/3 tone''' is a ratio of 13/12, and is about 139 cents.
** The 13-limit ''greater 2/3-tone'' is a ratio of [[13/12]], and is about 139{{c}}.
** The 17-limit '''large semitone''' is a ratio of 17/16, and is about 104 cents.
** The 17-limit ''large semitone'' is a ratio of [[17/16]], and is about 104{{c}}.
** The 17-limit '''small semitone''' is a ratio of 18/17, and is about 99 cents.
** The 17-limit ''small semitone'' is a ratio of [[18/17]], and is about 99{{c}}.


=== By delta ===
=== By delta ===
This table lists just semitones by [[Delta-N|delta]]:
This table lists just semitones by [[Delta-N|delta]]; simple semitone ratios tend to be [[Superparticular ratio|superparticular]].
{| class="wikitable"
{| class="wikitable"
|+
!Delta 1 (Superparticular)
!Cents
|-
|-
|[[13/12]]
! Delta 1 (Superparticular)
|139c
! Cents
|-
|-
|[[14/13]]
| [[13/12]]
|128c
| 139{{c}}
|-
|-
|[[15/14]]
| [[14/13]]
|119c
| 128{{c}}
|-
|-
|[[16/15]]
| [[15/14]]
|112c
| 119{{c}}
|-
|-
|[[17/16]]
| [[16/15]]
|104c
| 112{{c}}
|-
|-
|[[18/17]]
| [[17/16]]
|99c
| 104{{c}}
|-
|-
|[[19/18]]
| [[18/17]]
|94c
| 99{{c}}
|-
|-
|[[20/19]]
| [[19/18]]
|89c
| 94{{c}}
|-
|-
|[[21/20]]
| [[20/19]]
|85c
| 89{{c}}
|-
|-
|[[22/21]]
| [[21/20]]
|81c
| 85{{c}}
|-
|-
|[[23/22]]
| [[22/21]]
|77c
| 81{{c}}
|-
|-
|[[24/23]]
| [[23/22]]
|74c
| 77{{c}}
|-
|-
|[[25/24]]
| [[24/23]]
|71c
| 74{{c}}
|-
|-
|[[26/25]]
| [[25/24]]
|68c
| 71{{c}}
|-
|-
|[[27/26]]
| [[26/25]]
|65c
| 68{{c}}
|-
|-
|[[28/27]]
| [[27/26]]
|63c
| 65{{c}}
|-
|-
|[[29/28]]
| [[28/27]]
|61c
| 63{{c}}
|-
|-
|[[30/29]]
| [[29/28]]
|59c
| 61{{c}}
|-
|-
|[[31/30]]
| [[30/29]]
|57c
| 59{{c}}
|-
|-
|[[32/31]]
| [[31/30]]
|55c
| 57{{c}}
|-
|-
|[[33/32]]
| [[32/31]]
|53c
| 55{{c}}
|-
|-
|[[34/33]]
| [[33/32]]
|52c
| 53{{c}}
|-
|-
|[[35/34]]
| [[34/33]]
|50c
| 52{{c}}
|-
| [[35/34]]
| 50{{c}}
|}
|}


== In EDOs ==
== In EDOs ==
The following table lists the best tuning of 16/15, 25/24, and other semitones if present, in various significant [[EDOs]].
The following table lists the best tuning of 16/15, 25/24, and other semitones if present, in various significant [[edo|EDO]]s.
{| class="wikitable"
{| class="wikitable"
|+
!EDO
!16/15
!25/24
!Other semitones
|-
|-
|12
! EDO
| colspan="2" |100c
! 16/15
|
! 25/24
! Other semitones
|-
|-
|15
| 12
| colspan="2" |80c
| colspan="2" | 100{{c}}
|
|  
|-
|-
|16
| 15
| colspan="2" |75c
| colspan="2" | 80{{c}}
|
|  
|-
|-
|17
| 16
|141c
| colspan="2" | 75{{c}}
|71c
|  
|
|-
|-
|19
| 17
|126c
| 141{{c}}
|63c
| 71{{c}}
|
|  
|-
|-
|22
| 19
|109c
| 126{{c}}
|55c
| 63{{c}}
|
|  
|-
|-
|24
| 22
|100c
| 109{{c}}
|50c
| 55{{c}}
|
|  
|-
|-
|25
| 24
|96c
| 100{{c}}
|*
| 50{{c}}
|
|  
|-
|-
|26
| 25
| colspan="2" |92c
| 96{{c}}
|
| *
|  
|-
|-
|27
| 26
|133c
| colspan="2" | 92{{c}}
|89c
|  
|
|-
|-
|29
| 27
|124c
| 133{{c}}
|83c
| 89{{c}}
|
|  
|-
|-
|31
| 29
|116c
| 124{{c}}
|77c
| 83{{c}}
|
|  
|-
|-
|34
| 31
|106c
| 116{{c}}
|71c
| 77{{c}}
|
|  
|-
|-
|41
| 34
|117c
| 106{{c}}
|59c
| 71{{c}}
|88c ≈ 256/243
|  
|-
|-
|53
| 41
|113c
| 117{{c}}
|68c
| 59{{c}}
|91c ≈ 256/243
| {{nowrap|88{{c}} ≈ 256/243}}
|-
| 53
| 113{{c}}
| 68{{c}}
| {{nowrap|91{{c}} ≈ 256/243}}
|}
|}


== In regular temperaments ==
== In regular temperaments ==
Two important, simple semitone ratios are 16/15 and 25/24. The following notable temperaments are generated by them:
Two important, simple semitone ratios are 16/15 and 25/24. The following notable temperaments are generated by them:


=== Temperaments that use 25/24 as a generator ===
=== Temperaments that use 25/24 as a generator ===
 
* [[Valentine]], which divides [[3/2]] into nine small semitones, five of which make [[5/4]]. See also the related [[Carlos Alpha]].
* Vishnu, which stacks seven 25/24s to make a just [[perfect fourth]] of [[4/3]]
* [[Vishnu]], which stacks seven 25/24s to make a just [[perfect fourth]] of [[4/3]].
* Chlorine, equivalent to [[17edo]], stacking seventeen 25/24s to make an octave
* [[Chlorine]], based on [[17edo]], stacking seventeen 25/24s to make an octave.


=== Temperaments that use 16/15 as a generator ===
=== Temperaments that use 16/15 as a generator ===
* [[Miracle]], which splits [[3/2]] into six semitones, each representing both [[15/14]] and [[16/15]].
* [[Negri]], which splits [[4/3]] into four semitones, such that three of them represent [[5/4]].
* [[Diaschismic]], which is usually described as having a fifth as its second generator, but can alternatively be generated by a half-octave and a semitone.


* TBD
[[Compton]] has one step of [[12edo]] as its first generator, representing [[256/243]].
 


When 25/24 is tempered out, it leads to [[dicot]] temperament.
When 25/24 is tempered out, it leads to [[dicot]] temperament.


When 16/15 is tempered out, it leads to [[father]] temperament.
When 16/15 is tempered out, it leads to [[father]] temperament.
== In moment-of-symmetry scales ==
Intervals between 100 and 133{{c}} generate the following [[MOS]] scales:
These tables start from the last monolarge [[MOS]] generated by the interval range.
MOSes with more than 12 notes are not included.
{| class="wikitable"
|-
! Range
! colspan="2" | MOS
|-
| 100–109{{c}}
| [[1L 10s]]
| [[11L 1s]]
|-
| 109–120{{c}}
| [[1L 9s]]
| [[10L 1s]]
|-
| 120–133{{c}}
| [[1L 8s]]
| [[9L 1s]]
|}
== See also ==
* [[Semitone]] (disambiguation page)
{{Navbox intervals}}
{{Navbox intervals}}
[[Category:12edo]]
[[Category:12edo]]

Latest revision as of 10:08, 14 March 2025

← Comma and diesis Semitone, minor second, augmented unison Neutral second →
Name Semitone, minor second, augmented unison
Lower bound 60¢ – 75¢
Upper bound 125¢ – 140¢
Generated MOSes 1L 8s, 9L 1s, 1L 9s
Example JI intervals
Intervals 16/15 (111.7¢)
25/24 (70.7¢)
Related regions
Complement Major seventh
English Wikipedia has an article on:

A semitone, as a concrete interval region, is typically near 100 ¢ in size, distinct from commas and dieses (less than 60 ¢), and from neutral seconds (about 150 ¢). A rough tuning range for the semitone is about 60 ¢ to 125 ¢ according to Margo Schulter's theory of interval regions.

Functionally, a semitone is an interval that makes up part of a tone, often as one step of a 12-tone chromatic scale, which is a possible criterion for the classification of an interval as a semitone in just intonation.

Semitones come in two functional categories based on their number of steps in the diatonic scale:

The intervals covered in this article range from 50 ¢ to 140 ¢.

In just intonation

By prime limit

In the low prime limits, up to the 5-limit, in which the West has developed a formal system of diatonic harmony, the distinction between diatonic and chromatic semitones is the clearest, so a pair of 2 semitones will be provided for each. However, higher than the 5-limit, function as diatonic vs. chromatic tends to become less clear, and larger intervals can be seen as belonging to neither category.

  • In the 3-limit:
    • The limma, or Pythagorean diatonic semitone, is a ratio of 256/243, and is about 90 ¢.
    • The apotome, or Pythagorean chromatic semitone, is a ratio of 2187/2048, and is about 114 ¢.
  • In the 5-limit:
    • The classical diatonic semitone is a ratio of 16/15, and is about 112 ¢.
    • The classical chromatic semitone is a ratio of 25/24, and is about 71 ¢.
      • There is also a ptolemaic chromatic semitone, which is a ratio of 135/128, and is about 92 ¢.
  • In higher limits:
    • The 7-limit third-tone is a ratio of 28/27, and is about 63 ¢.
    • The 7-limit minor semitone is a ratio of 21/20, and is about 84 ¢.
    • The 7-limit major semitone is a ratio of 15/14, and is about 119 ¢.
    • The 11-limit minor semitone is a ratio of 22/21, and is about 81 ¢.
    • The 13-limit sinaic is a ratio of 14/13, and is about 128 ¢.
    • The 13-limit greater 2/3-tone is a ratio of 13/12, and is about 139 ¢.
    • The 17-limit large semitone is a ratio of 17/16, and is about 104 ¢.
    • The 17-limit small semitone is a ratio of 18/17, and is about 99 ¢.

By delta

This table lists just semitones by delta; simple semitone ratios tend to be superparticular.

Delta 1 (Superparticular) Cents
13/12 139 ¢
14/13 128 ¢
15/14 119 ¢
16/15 112 ¢
17/16 104 ¢
18/17 99 ¢
19/18 94 ¢
20/19 89 ¢
21/20 85 ¢
22/21 81 ¢
23/22 77 ¢
24/23 74 ¢
25/24 71 ¢
26/25 68 ¢
27/26 65 ¢
28/27 63 ¢
29/28 61 ¢
30/29 59 ¢
31/30 57 ¢
32/31 55 ¢
33/32 53 ¢
34/33 52 ¢
35/34 50 ¢

In EDOs

The following table lists the best tuning of 16/15, 25/24, and other semitones if present, in various significant EDOs.

EDO 16/15 25/24 Other semitones
12 100 ¢
15 80 ¢
16 75 ¢
17 141 ¢ 71 ¢
19 126 ¢ 63 ¢
22 109 ¢ 55 ¢
24 100 ¢ 50 ¢
25 96 ¢ *
26 92 ¢
27 133 ¢ 89 ¢
29 124 ¢ 83 ¢
31 116 ¢ 77 ¢
34 106 ¢ 71 ¢
41 117 ¢ 59 ¢ 88 ¢ ≈ 256/243
53 113 ¢ 68 ¢ 91 ¢ ≈ 256/243

In regular temperaments

Two important, simple semitone ratios are 16/15 and 25/24. The following notable temperaments are generated by them:

Temperaments that use 25/24 as a generator

Temperaments that use 16/15 as a generator

  • Miracle, which splits 3/2 into six semitones, each representing both 15/14 and 16/15.
  • Negri, which splits 4/3 into four semitones, such that three of them represent 5/4.
  • Diaschismic, which is usually described as having a fifth as its second generator, but can alternatively be generated by a half-octave and a semitone.

Compton has one step of 12edo as its first generator, representing 256/243.

When 25/24 is tempered out, it leads to dicot temperament.

When 16/15 is tempered out, it leads to father temperament.

In moment-of-symmetry scales

Intervals between 100 and 133 ¢ generate the following MOS scales:

These tables start from the last monolarge MOS generated by the interval range.

MOSes with more than 12 notes are not included.

Range MOS
100–109 ¢ 1L 10s 11L 1s
109–120 ¢ 1L 9s 10L 1s
120–133 ¢ 1L 8s 9L 1s

See also


ViewTalkEditInterval classification
Interval regions
Unison and octave UnisonComma and diesisOctave
Seconds Minor secondNeutral secondMajor second
Thirds Minor thirdNeutral thirdMajor third
Fourths and fifths Perfect fourthSuperfourthTritoneSubfifthPerfect fifth
Sixths Minor sixthNeutral sixthMajor sixth
Sevenths Minor seventhNeutral seventhMajor seventh
Interseptimal intervals Interseptimal 2nd-3rd • Interseptimal 3rd-4th • Interseptimal 5th-6th • Interseptimal 6th-7th
Interval qualities
Diatonic qualities DiminishedMinorPerfectMajorAugmented
Tuning ranges Neutral (interval quality)Submajor and supraminorPental major and minorNovamajor and novaminorNeogothic major and minorSupermajor and subminorUltramajor and inframinor