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Scale 993: "Gavian"

Scale 993: Gavian, Ian Ring Music Theory

Bracelet Diagram

The bracelet shows tones that are in this scale, starting from the top (12 o'clock), going clockwise in ascending semitones. The "i" icon marks imperfect tones that do not have a tone a fifth above. Dotted lines indicate axes of symmetry.

Tonnetz Diagram

Tonnetz diagrams are popular in Neo-Riemannian theory. Notes are arranged in a lattice where perfect 5th intervals are from left to right, major third are northeast, and major 6th intervals are northwest. Other directions are inverse of their opposite. This diagram helps to visualize common triads (they're triangles) and circle-of-fifth relationships (horizontal lines).

Common Names




Cardinality is the count of how many pitches are in the scale.

6 (hexatonic)

Pitch Class Set

The tones in this scale, expressed as numbers from 0 to 11


Forte Number

A code assigned by theorist Allen Forte, for this pitch class set and all of its transpositional (rotation) and inversional (reflection) transformations.


Rotational Symmetry

Some scales have rotational symmetry, sometimes known as "limited transposition". If there are any rotational symmetries, these are the intervals of periodicity.


Reflection Axes

If a scale has an axis of reflective symmetry, then it can transform into itself by inversion. It also implies that the scale has Ridge Tones. Notably an axis of reflection can occur directly on a tone or half way between two tones.



A palindromic scale has the same pattern of intervals both ascending and descending.



A chiral scale can not be transformed into its inverse by rotation. If a scale is chiral, then it has an enantiomorph.

enantiomorph: 249


A hemitone is two tones separated by a semitone interval. Hemitonia describes how many such hemitones exist.

4 (multihemitonic)


A cohemitone is an instance of two adjacent hemitones. Cohemitonia describes how many such cohemitones exist.

3 (tricohemitonic)


An imperfection is a tone which does not have a perfect fifth above it in the scale. This value is the quantity of imperfections in this scale.



Modes are the rotational transformations of this scale. This number does not include the scale itself, so the number is usually one less than its cardinality; unless there are rotational symmetries then there are even fewer modes.


Prime Form

Describes if this scale is in prime form, using the Rahn/Ring formula.

prime: 159


Indicates if the scale can be constructed using a generator, and an origin.


Deep Scale

A deep scale is one where the interval vector has 6 different digits.


Interval Structure

Defines the scale as the sequence of intervals between one tone and the next.

[5, 1, 1, 1, 1, 3]

Interval Vector

Describes the intervallic content of the scale, read from left to right as the number of occurences of each interval size from semitone, up to six semitones.

<4, 3, 3, 2, 2, 1>

Interval Spectrum

The same as the Interval Vector, but expressed in a syntax used by Howard Hanson.


Distribution Spectra

Describes the specific interval sizes that exist for each generic interval size. Each generic <g> has a spectrum {n,...}. The Spectrum Width is the difference between the highest and lowest values in each spectrum.

<1> = {1,3,5}
<2> = {2,4,6,8}
<3> = {3,5,7,9}
<4> = {4,6,8,10}
<5> = {7,9,11}

Spectra Variation

Determined by the Distribution Spectra; this is the sum of all spectrum widths divided by the scale cardinality.


Maximally Even

A scale is maximally even if the tones are optimally spaced apart from each other.


Maximal Area Set

A scale is a maximal area set if a polygon described by vertices dodecimetrically placed around a circle produces the maximal interior area for scales of the same cardinality. All maximally even sets have maximal area, but not all maximal area sets are maximally even.


Interior Area

Area of the polygon described by vertices placed for each tone of the scale dodecimetrically around a unit circle, ie a circle with radius of 1.


Polygon Perimeter

Perimeter of the polygon described by vertices placed for each tone of the scale dodecimetrically around a unit circle.


Myhill Property

A scale has Myhill Property if the Interval Spectra has exactly two specific intervals for every generic interval.



A scale is balanced if the distribution of its tones would satisfy the "centrifuge problem", ie are placed such that it would balance on its centre point.


Ridge Tones

Ridge Tones are those that appear in all transpositions of a scale upon the members of that scale. Ridge Tones correspond directly with axes of reflective symmetry.



Also known as Rothenberg Propriety, named after its inventor. Propriety describes whether every specific interval is uniquely mapped to a generic interval. A scale is either "Proper", "Strictly Proper", or "Improper".


Heteromorphic Profile

Defined by Norman Carey (2002), the heteromorphic profile is an ordered triple of (c, a, d) where c is the number of contradictions, a is the number of ambiguities, and d is the number of differences. When c is zero, the scale is Proper. When a is also zero, the scale is Strictly Proper.

(41, 9, 55)

Common Triads

These are the common triads (major, minor, augmented and diminished) that you can create from members of this scale.

* Pitches are shown with C as the root

Triad TypeTriad*Pitch ClassesDegreeEccentricityCloseness Centrality
Major TriadsF{5,9,0}210.67
Minor Triadsfm{5,8,0}121
Diminished Triadsf♯°{6,9,0}121

The following pitch classes are not present in any of the common triads: {7}

Parsimonious Voice Leading Between Common Triads of Scale 993. Created by Ian Ring ©2019 fm fm F F fm->F f#° f#° F->f#°

Above is a graph showing opportunities for parsimonious voice leading between triads*. Each line connects two triads that have two common tones, while the third tone changes by one generic scale step.

Central VerticesF
Peripheral Verticesfm, f♯°


Modes are the rotational transformation of this scale. Scale 993 can be rotated to make 5 other scales. The 1st mode is itself.

2nd mode:
Scale 159
Scale 159: Bamian, Ian Ring Music TheoryBamianThis is the prime mode
3rd mode:
Scale 2127
Scale 2127: Nafian, Ian Ring Music TheoryNafian
4th mode:
Scale 3111
Scale 3111: Tifian, Ian Ring Music TheoryTifian
5th mode:
Scale 3603
Scale 3603: Womian, Ian Ring Music TheoryWomian
6th mode:
Scale 3849
Scale 3849: Yikian, Ian Ring Music TheoryYikian


The prime form of this scale is Scale 159

Scale 159Scale 159: Bamian, Ian Ring Music TheoryBamian


The hexatonic modal family [993, 159, 2127, 3111, 3603, 3849] (Forte: 6-Z36) is the complement of the hexatonic modal family [111, 1923, 2103, 3009, 3099, 3597] (Forte: 6-Z3)


The inverse of a scale is a reflection using the root as its axis. The inverse of 993 is 249

Scale 249Scale 249: Boqian, Ian Ring Music TheoryBoqian


Only scales that are chiral will have an enantiomorph. Scale 993 is chiral, and its enantiomorph is scale 249

Scale 249Scale 249: Boqian, Ian Ring Music TheoryBoqian


In the abbreviation, the subscript number after "T" is the number of semitones of tranposition, "M" means the pitch class is multiplied by 5, and "I" means the result is inverted. Operation is an identical way to express the same thing; the syntax is <a,b> where each tone of the set x is transformed by the equation y = ax + b

Abbrev Operation Result Abbrev Operation Result
T0 <1,0> 993       T0I <11,0> 249
T1 <1,1> 1986      T1I <11,1> 498
T2 <1,2> 3972      T2I <11,2> 996
T3 <1,3> 3849      T3I <11,3> 1992
T4 <1,4> 3603      T4I <11,4> 3984
T5 <1,5> 3111      T5I <11,5> 3873
T6 <1,6> 2127      T6I <11,6> 3651
T7 <1,7> 159      T7I <11,7> 3207
T8 <1,8> 318      T8I <11,8> 2319
T9 <1,9> 636      T9I <11,9> 543
T10 <1,10> 1272      T10I <11,10> 1086
T11 <1,11> 2544      T11I <11,11> 2172
Abbrev Operation Result Abbrev Operation Result
T0M <5,0> 2643      T0MI <7,0> 2379
T1M <5,1> 1191      T1MI <7,1> 663
T2M <5,2> 2382      T2MI <7,2> 1326
T3M <5,3> 669      T3MI <7,3> 2652
T4M <5,4> 1338      T4MI <7,4> 1209
T5M <5,5> 2676      T5MI <7,5> 2418
T6M <5,6> 1257      T6MI <7,6> 741
T7M <5,7> 2514      T7MI <7,7> 1482
T8M <5,8> 933      T8MI <7,8> 2964
T9M <5,9> 1866      T9MI <7,9> 1833
T10M <5,10> 3732      T10MI <7,10> 3666
T11M <5,11> 3369      T11MI <7,11> 3237

The transformations that map this set to itself are: T0

Nearby Scales:

These are other scales that are similar to this one, created by adding a tone, removing a tone, or moving one note up or down a semitone.

Scale 995Scale 995: Phrathian, Ian Ring Music TheoryPhrathian
Scale 997Scale 997: Rycrian, Ian Ring Music TheoryRycrian
Scale 1001Scale 1001: Badian, Ian Ring Music TheoryBadian
Scale 1009Scale 1009: Katyptian, Ian Ring Music TheoryKatyptian
Scale 961Scale 961: Gabian, Ian Ring Music TheoryGabian
Scale 977Scale 977: Kocrimic, Ian Ring Music TheoryKocrimic
Scale 929Scale 929: Fujian, Ian Ring Music TheoryFujian
Scale 865Scale 865: Jahian, Ian Ring Music TheoryJahian
Scale 737Scale 737: Truian, Ian Ring Music TheoryTruian
Scale 481Scale 481: Dabian, Ian Ring Music TheoryDabian
Scale 1505Scale 1505: Jepian, Ian Ring Music TheoryJepian
Scale 2017Scale 2017: Meqian, Ian Ring Music TheoryMeqian
Scale 3041Scale 3041: Tanian, Ian Ring Music TheoryTanian

This scale analysis was created by Ian Ring, Canadian Composer of works for Piano, and total music theory nerd. Scale notation generated by VexFlow, graph visualization by Graphviz, and MIDI playback by MIDI.js. All other diagrams and visualizations are © Ian Ring. Some scale names used on this and other pages are ©2005 William Zeitler ( used with permission.

Pitch spelling algorithm employed here is adapted from a method by Uzay Bora, Baris Tekin Tezel, and Alper Vahaplar. (An algorithm for spelling the pitches of any musical scale) Contact authors Patent owner: Dokuz Eylül University, Used with Permission. Contact TTO

Tons of background resources contributed to the production of this summary; for a list of these peruse this Bibliography. Special thanks to Richard Repp for helping with technical accuracy, and George Howlett for assistance with the Carnatic ragas.