Xenharmonic Wiki

Interval size measure: Difference between revisions

← Older edit
VisualWikitext
Xenwolf (talk | contribs)
autopatrolled, Bureaucrats, confirmaccount-notify, Interface administrators, Sysops
8,705 edits
→Non-octave fine measures: add conversion formula
Update
 
(65 intermediate revisions by 14 users not shown)
Line 2: Line 2:


== Logarithmic ==
== Logarithmic ==
All logarithmic measures can be combined by adding and subtracting them.


All logarithmic measures can be combined by adding and subtracting them.
=== Backslash notation ===
A common shorthand in use in the microtonal community is ''k''\''N'', written with a backslash (\) instead of a forwardslash (/), to refer to an interval with a frequency ratio of 2<sup>''k''/''N''</sup>. ''k''\''N'' is pronounced "''k'' steps of ''N'' [[edo]]", and can be derived from the meaning of "[[step]]s" in the context of edos (unless talking about steps of specific subsets/scales of some edo).
 
Steps are linear in the log-frequency domain, so expressions like {{nowrap|11\19 − 6\19 {{=}} 5\19}} hold. In general, we have
: {{nowrap|''a''\''N'' + ''b''\''N'' {{=}} (''a'' + ''b'')\''N''}}
 
which expresses the same thing as {{nowrap|2<sup>''a''/''N''</sup> × 2<sup>''b''/''N''</sup> {{=}} 2<sup>(''a'' + ''b'')/''N''</sup>.}}
 
Or equivalently, for subtraction/division:
 
: {{nowrap|''a''\''N'' − ''b''\''N'' {{=}} (''a'' − ''b'')\''N''}}
 
which expresses the same thing as {{nowrap|2<sup>''a''/''N''</sup> / 2<sup>''b''/''N''</sup> {{=}} 2<sup>(''a'' - ''b'')/''N''</sup>.}}
 
Backslash notation can be extended to support [[nonoctave]] [[equal tuning]]s by writing the tuning in full after the backslash. For example, 11\13edt means 11 steps of [[13edt]], 14\9edf means 14 steps of [[9edf]], and 7\12ed12/5 means 7 steps of [[12ed12/5]].


=== Gross ===
=== Gross ===
The [[octave]] and the [[decade]] are common coarse units for interval sizes. The {{w|decibel}}, being a relative logarithmic-scale unit for power or root-power quantities, is inappropriate for measuring intervals; the decade is used instead. Similarly, the {{w|neper}} (Np) and the dineper (dNp), like the decibel, should not be used. However, in the absence of a substitute, dinepers have an application in [[logarithmic approximants]].


Intervals are sometimes expressed in the number of scale steps between them. These steps can be of different size, compare for example the names of the major scale in the classic music. An early unit for measuring intervals is the "[[tone]]" which dates back to classic Greece.
Intervals are sometimes expressed in the number of scale steps between them. These steps can be of different size, compare for example the names of the major scale in the classic music. An early unit for measuring intervals is the "[[tone]]" which dates back to classic Greece.


In serial music all intervals were measured by the number of 12edo-semitones. In analogy, the '''relative interval measure''' is the number of steps between two pitches of an [[Equal-step tuning|equal]] tuning, sometimes called "[[degree]]s" (of an edo). For generators, the backslash notation is used d\edo, but it is also a ratio (of a logarithmic measure).
In serial music, all intervals were measured by the number of 12edo [[semitone (interval size measure)|semitone]]s. In analogy, the '''relative interval measure''' is the number of steps between two pitches of an [[equal tuning]], sometimes called "[[degree]]s". These measures can be written using [[#Backslash notation|backslash notation]] if the degree itself isn't sufficiently clear in context.


=== Fine ===
=== Fine ===
The [[cent]] (¢), [[1200edo|1\1200 octave]], is the classic measure for intervals when more precision than 12edo is required. Some people object to it on the grounds that it is too (obviously) closely related to 12 equal.  
The [[cent]] (¢), [[1200edo|1\1200 octave]], is the classic measure for intervals when more precision than 12edo is required. Some people object to it on the grounds that it is too (obviously) closely related to 12 equal.  


==== Octave-based fine measures ====
==== Octave-based fine measures ====
The following table demonstrates a list of measures derived from the logarithmic division of the octave: {{todo|complete table|research|comment=Add all missing citations.}}


The following table demonstrates a list of measures derived from the logarithmic division of the octave:
{| class="wikitable sortable"
{| class="wikitable sortable"
|+ List of Octave-Based Fine Measures (Logarithmic)
|+ style="font-size: 105%;" | List of octave-based fine measures (logarithmic)
|-
|-
! Unit name (symbol):
! Unit name (symbol):
! Divisions of Octave
! Divisions of octave
! Prime Factors
! Prime factors
! Origin / Significance
! Origin/significance
|-
|-
| [[Eka]]
| [[Eka]]
| [[16edo|16]]
| [[16edo|16]]
| 2<sup>4</sup>
| 2<sup>4</sup>
| From Sanskrit ''eka'': one, unit; chromatic unit of Armodue 16ED2 Theory
| From Sanskrit ''eka'': one, unit; chromatic unit of Armodue 16edo theory<ref>[http://www.armodue.com/risorse.htm Armodue: le risorse di un nuovo sistema musicale]</ref>.
|-
| [[Normal shruti]]
| [[22edo|22]]
| 2 × 11
| Proposed by [[User:Tristanbay|Tristan Bay]] (2025) in reference to the Indian tradition of dividing the octave into 22 unequal parts.
|-
|-
| [[Normal diesis]]
| [[Normal diesis]]
| [[31edo|31]]
| [[31edo|31]]
| PRIME
| 31 (prime)
|
| See the dedicated page.
|-
| [[Dea]]
| [[41edo|41]]
| 41 (prime)
| Proposed by [[User:Tristanbay|Tristan Bay]] (2025) to reflect that a mina is a "minute" (1/60 the width) of a 1\41 "degree".
|-
|-
| [[Méride]]
| [[Méride]]
| [[43edo|43]]
| [[43edo|43]]
| PRIME
| 43 (prime)
| Proposed by Joseph Sauveur, as 7 heptaméride units ([http://tonalsoft.com/enc/m/meride.aspx source])
| Proposed by [[Joseph Sauveur]], as 7 heptaméride units<ref name="measure">[http://www.huygens-fokker.org/docs/measures.html Stichting Huygens–Fokker: Logarithmic Interval Measures]</ref><ref>[http://tonalsoft.com/enc/m/meride.aspx Tonalsoft | ''Méride / 43-ed2 / 43-edo / 43-ET / 43-tone equal-temperament'']</ref>.
|-
|-
| [[Holdrian comma]]
| [[Holdrian comma]]
| [[53edo|53]]
| [[53edo|53]]
| PRIME
| 53 (prime)
|
| See the dedicated page.
|-
| [[Holdrian comma|Mercator's old comma]]
| [[55edo|55]]
| 5 × 11
| Not to be confused with [[Mercator's comma]].
|-
| [[Decitone]]
| [[60edo|60]]
| 2<sup>2</sup> × 3 × 5
| Standard SI prefix + 12edo tone
|-
|-
| [[Morion]]
| [[Morion]]
| [[72edo|72]]
| [[72edo|72]]
| 2<sup>3</sup> × 3<sup>2</sup>
| 2<sup>3</sup> × 3<sup>2</sup>
|
| See the dedicated page.
|-
|-
| [[Farab]]
| [[Farab]]
| [[144edo|144]]
| [[144edo|144]]
| 2<sup>4</sup> × 3<sup>2</sup>
| 2<sup>4</sup> × 3<sup>2</sup>
| 1/12 of [[12ED2]] semitone; Proposed by al-Farabi in 10th century ([http://www.huygens-fokker.org/docs/measures.html source])
| 1/12 of [[12edo]] semitone; proposed by [[al-Farabi]] in 10th century<ref name="measure"/><ref>[http://tonalsoft.com/enc/f/farab.aspx Tonalsoft | ''Farab''].</ref>.
|-
|-
| [[Mem]]
| [[Mem]]
| [[205edo|205]]
| [[205edo|205]]
| 5 × 41
| 5 × 41
| Unit used by [http://musictheory.zentral.zone/huntsystem1.html H-Pi Instruments]
| Unit used by H-Pi Instruments<ref name="measure"/><ref>[http://musictheory.zentral.zone/huntsystem1.html H-Pi Instruments | Hunt Theoretical System]</ref><ref>[http://tonalsoft.com/enc/m/mem.aspx Tonalsoft | ''Mem, 205-edo'']</ref>.
|-
|-
| [[Tredek]]
| [[Tredek]]
| [[270edo|270]]
| [[270edo|270]]
| 2 × 3<sup>3</sup> × 5
| 2 × 3<sup>3</sup> × 5
|
| Proposed by [[Joseph Monzo]] (2013)<ref>[http://tonalsoft.com/enc/t/tredek.aspx Tonalsoft | ''Tredek, 270-edo'']</ref>.
|-
|-
| [[Savart]]*
| [[Savart]]*
| [[300edo|300]]
| [[300edo|300]]
| 2<sup>2</sup> × 3 × 5<sup>2</sup>
| 2<sup>2</sup> × 3 × 5<sup>2</sup>
| Alexander Wood's definition of the Savart (''[https://books.google.com.au/books?id=NWZ8CgAAQBAJ&lpg=PT50&vq=savart&pg=PT51 The Physics of Music]'', 1944), compatible with [[12ED2]] system
| [[Alexander Wood]]'s definition of the Savart<ref>''[https://books.google.com.au/books?id=NWZ8CgAAQBAJ&lpg=PT50&vq=savart&pg=PT51 The Physics of Music]'', Alexander Wood, 1944.</ref>, containing [[12edo]]. 
|-
|-
| [[Heptaméride]]/[[Eptaméride]]/[[Savart]]*
| [[Heptaméride]] / [[eptaméride]] / [[savart]]*
| [[301edo|301]]
| [[301edo|301]]
| 7 × 43
| 7 × 43
| 301 ≃ 1,000 * log<sub>10</sub>2; 1/7 of Méride unit; Proposed by Joseph Sauveur ([http://www.tonalsoft.com/enc/e/equal-temperament.aspx 1701]), advocated by Félix Savart
| 301 ≃ 1,000 × log<sub>10</sub>2; 1/7 of Méride unit; proposed by Joseph Sauveur (1701), advocated by [[Félix Savart]]<ref name="measure"/><ref>[http://tonalsoft.com/enc/h/heptameride.aspx Tonalsoft | ''Heptaméride'']</ref>.
|-
|-
| [[Gene]]
| [[Gene]]
| [[311edo|311]]
| [[311edo|311]]
| PRIME
| 311 (prime)
|
| Proposed by Joseph Monzo (2007)<ref>[http://tonalsoft.com/enc/g/gene.aspx Tonalsoft | ''Gene, 311-edo'']</ref>.
|-
|-
| [[Dröbisch_Angle|Dröbisch Angle]]
| [[Dröbisch Angle]]
| [[360edo|360]]
| [[360edo|360]]
| 2<sup>3</sup> × 3<sup>2</sup> × 5
| 2<sup>3</sup> × 3<sup>2</sup> × 5
|
| Proposed as ''angle'' by [[Moritz Dröbisch]] in the 19th century, later by [[Andrew Pikler]] as the current name in ''Logarithmic Frequency Systems'' (1966)<ref name="measure"/>.
|-
|-
| [[Squb]]
| [[Squb]]
| [[494edo|494]]
| [[494edo|494]]
| 2 × 13 × 19
| 2 × 13 × 19
|
| Named after [[729/728]], the squbema, due to its similar size.
|-
| [[Great iring]] / [[great centitone|centitone]]
| [[500edo|500]]
| 2<sup>2</sup> × 5<sup>3</sup>
| {{Citation needed}}
|-
| Dexl
| [[540edo|540]]
| 2<sup>2</sup> × 3<sup>3</sup> × 5
| Proposed by Joseph Monzo (2023)<ref>[http://tonalsoft.com/enc/d/dexl.aspx Tonalsoft | ''Dexl, 540-edo'']</ref>.
|-
|-
| [[Iring]]/[[Centitone]]
| [[Iring]] / [[centitone]]
| [[600edo|600]]
| [[600edo|600]]
| 2<sup>3</sup> × 3 × 5<sup>2</sup>
| 2<sup>3</sup> × 3 × 5<sup>2</sup>
| [[Relative cent]] of [[6ED2]] ([[12ED2]] tone); Proposed by Widogast Iring (1898), later by Joseph Yasser as a "centitone" (1932). ([http://www.tonalsoft.com/enc/c/centitone.aspx source])
| [[Relative cent]] of [[6edo]]; proposed by [[Widogast Iring]] (1898), later by [[Joseph Yasser]] as a "centitone", a standard SI prefix + 12edo tone (1932)<ref name="measure"/><ref>[http://www.tonalsoft.com/enc/c/centitone.aspx Tonalsoft | ''Centitone, iring'']</ref>.
|-
|-
| [[Skisma]]
| [[Nil]] / [[skisma]] (Sk)
| [[612edo|612]]
| [[612edo|612]]
| 2<sup>2</sup> × 3<sup>2</sup> × 17
| 2<sup>2</sup> × 3<sup>2</sup> × 17
| ED2 representation of [[Sagittal notation|Sagittal]]'s Ultra (Herculean) precision level JI notation (58-EDA), where it is known as an "ultrina"
| Proposed by [[James Paul White]] (1894) as ''nil'', and by Gene Ward Smith (2007) as ''skisma''<ref name="measure"/><ref>[http://tonalsoft.com/enc/s/sk.aspx Tonalsoft | ''Sk, 612-edo'']</ref>. Edo representation of [[Sagittal notation|Sagittal]]'s Ultra (Herculean) precision level JI notation (58eda), where it is known as an "ultrina".
|-
|-
| [[Delfi]]
| [[Delfi]]
| [[665edo|665]]
| [[665edo|665]]
| 5 × 7 × 19
| 5 × 7 × 19
|
| <ref name="measure"/>
|-
| [[Small iring]] / [[small centitone|centitone]]
| [[700edo|700]]
| 2<sup>2</sup> × 5<sup>2</sup> x 7
| {{Citation needed}}
|-
|-
| [[Woolhouse]]
| [[Woolhouse unit]]
| [[730edo|730]]
| [[730edo|730]]
| 2 × 5 × 73
| 2 × 5 × 73
| Proposed by Wesley S.B. Woolhouse in [https://archive.org/details/essayonmusicali00woolgoog/page/n34/mode/2up ''Essay on musical intervals''] (1835)
| Proposed by [[Wesley S.B. Woolhouse]] (1835)<ref>[https://archive.org/details/essayonmusicali00woolgoog/page/n34/mode/2up ''Essay on musical intervals, harmonics, and the temperament of the musical scale, &c''], Wesley S.B. Woolhouse. </ref>.
|-
|-
| [[millioctave]] (mO)
| [[Millioctave]] (moct)
| [[1000edo|1000]]
| [[1000edo|1000]]
| 2<sup>3</sup> × 5<sup>3</sup>
| 2<sup>3</sup> × 5<sup>3</sup>
| [https://en.wikipedia.org/wiki/Metric_prefix SI-prefix] division of octave
| See the dedicated page.  
|-
|-
| [[cent]] (¢)
| [[Cent]] (¢)
| 1200
| 1200
| 2<sup>4</sup> × 3 × 5<sup>2</sup>
| 2<sup>4</sup> × 3 × 5<sup>2</sup>
| 1/100 of [[12ED2]] semitone
| See the dedicated page.
|-
| greater muon
| [[1224edo|1224]]
| 2<sup>3</sup> × 3<sup>2</sup> × 17
|
|-
| triangular cent
| [[1260edo|1260]]
| 2<sup>2</sup> × 3<sup>2</sup> × 5 × 7
|
|-
| pion
| [[1272edo|1272]]
| 2<sup>3</sup> × 3 × 53
|
|-
| pound
| [[1344edo|1344]]
| 2<sup>6</sup> × 3 × 7
|
|-
|-
| neutron
| Dingle
| [[1392edo|1392]]
| [[1395edo|1395]]
| 2<sup>4</sup> × 3 × 29
| 3<sup>2</sup> × 5 × 31
|
| Proposed by [[User:Tristanbay|Tristan Bay]] (2026) as a 31edo-friendly fine-grain measure, shortened from "'''di'''esis a'''ngle'''".
|-
|-
| lesser muon
| Decifarab
| [[1428edo|1428]]
| 2<sup>2</sup> × 3 × 7 × 17
|
|-
| deciFarab
| [[1440edo|1440]]
| [[1440edo|1440]]
| 2<sup>5</sup> × 3<sup>2</sup> × 5
| 2<sup>5</sup> × 3<sup>2</sup> × 5
| 1/10 of [[Farab]] unit
| Standard SI prefix + [[farab]]<ref name="measure"/>.
|-
| quadratic cent
| [[1452edo|1452]]
| 2<sup>2</sup> × 3 × 11<sup>2</sup>
|
|-
| ksion
| [[1476edo|1476]]
| 2<sup>2</sup> × 3<sup>2</sup> × 41
|
|-
| cubic cent
| [[1500edo|1500]]
| 2<sup>2</sup> × 3 × 5<sup>3</sup>
|
|-
|-
| 7mu
| Heptamu (7mu)
| [[1536edo|1536]]
| [[1536edo|1536]]
| 2<sup>9</sup> × 3
| 2<sup>9</sup> × 3
| (7th MIDI unit), seventh MIDI-resolution unit, 1/128 (1/(2<sup>7</sup>)) of [[12ED2]] semitone
| Seventh MIDI-resolution unit, 1/128 (1/(2<sup>7</sup>)) of [[12edo]] semitone<ref>[http://tonalsoft.com/enc/number/7mu.aspx Tonalsoft | ''7mu / heptamu'']</ref>
|-
| rhoon
| [[1560edo|1560]]
| 2<sup>3</sup> × 3 × 5 × 13
|
|-
|-
| tile
| śata
| [[1632edo|1632]]
| [[1600edo|1600]]
| 2<sup>5</sup> × 3 × 17
| 2<sup>6</sup> × 5<sup>2</sup>  
|
| From Sanskrit ''śatam'': hundred; [[relative cent]] of Armodue 16edo theory{{Citation needed}}
|-
|-
| [[Iota]]
| [[Iota]]
| [[1\1700_octave|1700]]
| [[1700edo|1700]]
| 2<sup>2</sup> × 5<sup>2</sup> × 17
| 2<sup>2</sup> × 5<sup>2</sup> × 17
| [[Relative cent]] of [[17ED2]]; proposed by [[Margo Schulter]] ([http://www.huygens-fokker.org/docs/measures.html source]) and [[George Secor]] ([[Relative_cent|source]])
| [[Relative cent]] of [[17edo]]; proposed by [[Margo Schulter]] (2002) and [[George Secor]]<ref name="measure"/>.
|-
|-
| [[Harmos]]
| [[Harmos]]
| [[1728edo|1728]]
| [[1728edo|1728]]
| 2<sup>6</sup> × 3<sup>3</sup>
| 2<sup>6</sup> × 3<sup>3</sup>
| 1728 = 12<sup>3</sup>; 1/144 of [[12ED2]] semitone; Proposed by Paul Beaver ([http://www.tonalsoft.com/enc/e/equal-temperament.aspx source])
| 1728 = 12<sup>3</sup>; 1/144 of [[12edo]] semitone; Proposed by [[Paul Beaver]]<ref name="measure"/><ref name="equal">[http://tonalsoft.com/enc/e/equal-temperament.aspx Tonalsoft | ''Equal temperaments'']</ref>.
|-
| Hind śat / Indian cent
| 2200
| 2<sup>3</sup> × 11 × 5<sup>2</sup>
| {{Citation needed}}
|-
|-
| [[Mina]]
| [[Mina]]
| [[2460edo|2460]]
| [[2460edo|2460]]
| 2<sup>2</sup> × 3 × 5 × 41
| 2<sup>2</sup> × 3 × 5 × 41
| Abbreviation of "schismina", ED2 representation of [[Sagittal notation|Sagittal]]'s Extreme (Olympian) precision level JI notation (233 -EDA)
| Abbreviation of "schismina", edo representation of [[Sagittal notation|Sagittal]]'s Extreme (Olympian) precision level JI notation (233eda)<ref name="measure"/><ref>[http://tonalsoft.com/enc/m/mina.aspx Tonalsoft | ''Mina'']</ref>.
|-
| Centidiesis
| 3100
| 2<sup>2</sup> × 5<sup>2</sup> x 31
| {{Citation needed}}
|-
| Centiméride
| 4300
| 2<sup>2</sup> × 5<sup>2</sup> x 43
| {{Citation needed}}
|-
| [[4320edo|Click]]
| [[4320edo|4320]]
| 2<sup>5</sup> × 3<sup>3</sup> × 5
| Proposed by [[User:Eliora|Eliora]]. See the dedicated page.
|-
| [[Major tina]]
| [[8269edo|8269]]
| 8269 (prime)
| Proposed by [[Flora Canou]] (2021)<ref>[https://forum.sagittal.org/viewtopic.php?f=4&t=515 The Sagittal Forum | ''Definition of the tina reviewed'']</ref>.
|-
|-
| [[Tina]]
| [[Tina]]
| [[8539edo|8539]]
| [[8539edo|8539]]
| PRIME
| 8539 (prime)
| Provides good approximations for 41-limit primes except 37 ([http://www.tonalsoft.com/enc/t/tina.aspx source]); named by [[Dave Keenan]] and [[George Secor]]; ED2 representation of [[Sagittal notation|Sagittal]]'s Insane (Magrathean) precision level JI notation (809-EDA)
| Provides good approximations for 41-limit primes except 37; named by [[Dave Keenan]] and [[George Secor]]; edo representation of [[Sagittal notation|Sagittal]]'s Insane (Magrathean) precision level JI notation (809eda)<ref name="measure"/><ref>[http://tonalsoft.com/enc/t/tina.aspx Tonalsoft | ''Tina'']</ref>.
|-
|-
| [[Purdal]]
| [[Purdal]]
| [[9900edo|9900]]
| [[9900edo|9900]]
| 2<sup>2</sup> × 3<sup>2</sup> × 5<sup>2</sup> × 11
| 2<sup>2</sup> × 3<sup>2</sup> × 5<sup>2</sup> × 11
| [[Relative cent]] of [[99edo|99ED2]]; Suggested by [[Osmiorisbendi]], advocated by [[Tútim Dennsuul Wafiil]]  
| [[Relative cent]] of [[99edo]]; suggested by [[Osmiorisbendi]], advocated by [[Tútim Dennsuul Wafiil]]. See the dedicated page.
|-
|-
| [[Türk sent]] / [[Turkish cent]]
| [[Türk sent]] / [[Turkish cent]]
| [[10600edo|10600]]
| [[10600edo|10600]]
| 2<sup>3</sup> × 5<sup>2</sup> × 53
| 2<sup>3</sup> × 5<sup>2</sup> × 53
| [[Relative cent]] of [[106ED2]], 1/200 of [[53ED2]]; invented by [http://www.tonalsoft.com/enc/t/turk-sent.aspx M. Ekrem Karadeniz] (1965), influenced by  [https://core.ac.uk/download/pdf/76124322.pdf Abdülkadir Töre]
| [[Relative cent]] of [[106edo]], 1/200 of [[53edo]]; invented by [[M. Ekrem Karadeniz]] (1965), influenced by [[Abdülkadir Töre]]<ref name="measure"/><ref>[http://www.tonalsoft.com/enc/t/turk-sent.aspx Tonalsoft | ''Türk-sent'']</ref><ref>[http://www.ozanyarman.com/files/doctorate_thesis.pdf ''79-Tone Tuning & Theory for Turkish Maqam Music''], Ozan Yarman. </ref>.  
|-
|-
| [[Prima]]
| [[Prima]]
| [[12276edo|12276]]
| [[12276edo|12276]]
| 2<sup>2</sup> × 3<sup>2</sup> × 11 × 31
| 2<sup>2</sup> × 3<sup>2</sup> × 11 × 31
|
| Proposed by [[Erv Wilson]], [[Gene Ward Smith]] and [[Gavin Putland]]<ref name="measure"/>.
|-
|-
| [[Jinn]]
| [[Jinn]]
| [[16808edo|16808]]
| [[16808edo|16808]]
| 2<sup>3</sup> × 11 × 191
| 2<sup>3</sup> × 11 × 191
|
| See the dedicated page.
|-
|-
| [[Jot]]
| [[Jot]]
| [[30103edo|30103]]
| [[30103edo|30103]]
| PRIME
| 30103 (prime)
| 30103 ≃ 100,000 * log<sub>10</sub>2; Proposed by [http://www.tonalsoft.com/enc/j/jot.aspx Augustus de Morgan]([http://tonalsoft.com/enc/e/equal-temperament.aspx 1864])
| 30103 ≃ 100,000 × log<sub>10</sub>2; proposed by [[Augustus de Morgan]] (1864)<ref name="measure"/><ref>[http://www.tonalsoft.com/enc/j/jot.aspx Tonalsoft | ''Jot'']</ref><ref name="equal"/>.  
|-
|-
| [[Imp]]
| [[Imp]]
| [[31920edo|31920]]
| [[31920edo|31920]]
| 2<sup>4</sup> × 3 × 5 × 7 × 19
| 2<sup>4</sup> × 3 × 5 × 7 × 19
|
| <ref name="measure"/>
|-
|-
| [[Flu]]
| [[Flu]]
| [[46032edo|46032]]
| [[46032edo|46032]]
| 2<sup>4</sup> × 3 × 7 × 137
| 2<sup>4</sup> × 3 × 7 × 137
|
| Proposed by Gene Ward Smith (2005)<ref name="measure"/><ref>[http://tonalsoft.com/enc/f/flu.aspx Tonalsoft | ''Flu'']</ref>.
|-
| [[Normal atom]]
| [[78005edo|78005]]
| 5 × 15601
| Proposed by Tristan Bay (2023); 78005edo consistently maps Kirnberger's atom to 1 edostep and is a very strong 5-limit system.
|-
|-
| [[MIDI_Tuning_Standard_unit|MIDI Tuning Standard unit]]
| [[MIDI Tuning Standard unit]] (14mu)
| [[196608edo|196608]]
| [[196608edo|196608]]
| 2<sup>16</sup> × 3
| 2<sup>16</sup> × 3
| 14mu (14th MIDI unit), fourteenth MIDI-resolution unit, 1/16384 (1/(2<sup>14</sup>)) of [[12edo|12ED2]] semitone
| Fourteenth MIDI-resolution unit, 1/16384 (1/(2<sup>14</sup>)) of [[12edo]] semitone<ref name="measure"/>.
|}
|}
 
<nowiki />* More to be added regarding the Heptaméride/Savart units
<nowiki>*</nowiki> More to be added regarding the Heptaméride/Savart units


==== Non-octave fine measures ====
==== Non-octave fine measures ====
There are other fine measurements based upon the logarithmic division of other intervals (e.g. 3/1 (twelfth)), a few of which are listed below:
There are other fine measurements based upon the logarithmic division of other intervals (e.g. 3/1 (twelfth)), a few of which are listed below:


{| class="wikitable sortable"
{| class="wikitable sortable"
|+ style="font-size: 105%;" | List of non-octave fine measures (logarithmic)
|-
|-
|+ List of Non-Octave Fine Measures (Logarithmic)
! Unit name (symbol)
! Base interval
! Divisions of base interval
! Origin/significance
|-
|-
! Unit name (symbol):
| Hekt
! Base interval:
| 3/1 (twelfth)
! Parts of base interval:
| 1300
! Origin/Significance
| 1/100 of 13edt (Bohlen–Pierce) scale step
|-
|-
| [[Hekt]]
| Euhekt
| 3/1 (twelfth)
| 3/1 (twelfth)
| 1300
| 3900
| 1/100 of 13-ED3 (Bohlen-Pierce) scale step
| 1/100 of 39edt (Triboh) scale step
|-
|-
| [[Grad]]
| Grad
| 531441/524288 (Pythagorean comma)
| [[Pythagorean comma|531441/524288]] (Pythagorean comma)
| 12
| 12
|
| [[12edo]] flattens [[3/2]] by this amount
|-
|-
| [[Tuning unit]]
| Tuning unit
| 531441/524288 (Pythagorean comma)
| [[531441/524288]] (Pythagorean comma)
| 720
| 720
|
|
Line 280: Line 317:
To ''convert hekts'', which is quite common in EDT systems, ''into cents'', use following formula: <code> c = h*12/13*math.log(3)/math.log(2) </code>
To ''convert hekts'', which is quite common in EDT systems, ''into cents'', use following formula: <code> c = h*12/13*math.log(3)/math.log(2) </code>


See [http://www.huygens-fokker.org/docs/measures.html Logarithmic Interval Measures]
=== Relative measures ===
Within a given [[equal-step tuning|equal-stepped tuning system]], the [[relative cent]] (rct, r¢) can be used to describe properties of pitches (for instance the approximation of [[Just intonation|JI]] intervals). It is defined as on 100th (or 1 percent) of the interval between two neighbouring pitches in the used equal tuning.


=== Relative measures ===
== Ratio ==
Intervals can be measured also giving their [[ratio]]. For instance the major third as [[5/4]] or the pure fifth [[3/2]]. When combining sizes given in ratios, you have to multiply or divide:


Within a given [[Equal-step tuning|equal]]-stepped tonal system, the [[relative cent]] (rct, r¢) can be used to describe properties of pitches (for instance the approximation of [[Just intonation|JI]] intervals). It is defined as on 100th (or 1 percent) of the interval between two neighbouring pitches in the used equal tuning.
a pure fifth increased by a major third gives the major seventh {{nowrap|3/2 × 5/4 {{=}} [[15/8]]}},


see also: Kirnberger Atom http://arxiv.org/abs/0907.5249
which is a diatonic semitone below an octave {{nowrap|([[2/1]]) / (15/8) {{=}} 2/1 × 8/15 {{=}} [[16/15]]}}.


== Ratio ==
Another notation for ratios is a vector of prime factor exponents, often called a [[monzo]], such as {{monzo| -4 4 -1 }} (for the syntonic comma, {{nowrap|81/80 = 2<sup>−4</sup> × 3<sup>4</sup> × 5<sup>−1</sup>}}), which builds a bridge back to the logarithmic measure: intervals can be combined by component-wise addition or subtraction of their vectors.
Intervals can be measured also giving their [http://en.wikipedia.org/wiki/Interval_ratio (frequency) ratio]. For instance the major third as [[5/4]] or the pure fifth [[3/2]]. When combining sizes given in ratios, you have to multiply or divide:


a pure fifth increased by a major third gives the major seventh 3/2 * 5/4 = [[15/8]],
== See also ==
* [[Interval span]]


which is a diatonic semitone below an octave ([[2/1]]) / (15/8) = 2/1 * 8/15 = [[16/15]].
== Articles ==
* [http://arxiv.org/abs/0907.5249 ''Why the Kirnberger Kernel Is So Small''] by [[Don N. Page]]


Another notation for ratios is a vector of prime factor exponents, often called a [[monzo]], such as {{monzo| -4 4 -1 }} (for the syntonic comma, 81/80 = 2^(-4) * 3^4 * 5^(-1)), which builds a bridge back to the logarithmic measure: intervals can be combined by component-wise addition or subtraction of their vectors.
== References ==
<references />


[[Category:Interval size]]
[[Category:Interval]]
[[Category:Interval size measure]]
[[Category:Measure]]
[[Category:Size]]
[[Category:Theory]]
Retrieved from "https://en.xen.wiki/w/Interval_size_measure"