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Scale 3647: "Nonatonic Chromatic 4"

Scale 3647: Nonatonic Chromatic 4, 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

Western Modern
Nonatonic Chromatic 4
Western
Chromatic Nonamode 6th Rotation
Zeitler
Eporygic
Dozenal
SHUian

Analysis

Cardinality

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

9 (enneatonic)

Pitch Class Set

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

{0,1,2,3,4,5,9,10,11}

Forte Number

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

9-1

Rotational Symmetry

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

none

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.

[1]

Palindromicity

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

no

Chirality

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

no

Hemitonia

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

8 (multihemitonic)

Cohemitonia

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

7 (multicohemitonic)

Imperfections

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.

3

Modes

Modes are the rotational transformations of this scale. This number includes the scale itself, so the number is usually the same as its cardinality; unless there are rotational symmetries then there are fewer modes.

9

Prime Form

Describes if this scale is in prime form, using the Starr/Rahn algorithm.

no
prime: 511

Generator

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

generator: 1
origin: 9

Deep Scale

A deep scale is one where the interval vector has 6 different digits, an indicator of maximum hierarchization.

no

Interval Structure

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

[1, 1, 1, 1, 1, 4, 1, 1, 1]

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.

<8, 7, 6, 6, 6, 3>

Proportional Saturation Vector

First described by Michael Buchler (2001), this is a vector showing the prominence of intervals relative to the maximum and minimum possible for the scale's cardinality. A saturation of 0 means the interval is present minimally, a saturation of 1 means it is the maximum possible.

<1, 0.5, 0, 0, 0, 0>

Interval Spectrum

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

p6m6n6s7d8t3

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

Spectra Variation

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

2.667

Maximally Even

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

no

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.

no

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.

2.433

Polygon Perimeter

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

5.873

Myhill Property

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

yes

Centre of Gravity Distance

When tones of a scale are imagined as physical objects of equal weight arranged around a unit circle, this is the distance from the center of the circle to the center of gravity for all the tones. A perfectly balanced scale has a CoG distance of zero.

0.303562

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.

[2]

Propriety

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".

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.

(140, 35, 120)

Coherence Quotient

The Coherence Quotient is a score between 0 and 1, indicating the proportion of coherence failures (ambiguity or contradiction) in the scale, against the maximum possible for a cardinality. A high coherence quotient indicates a less complex scale, whereas a quotient of 0 indicates a maximally complex scale.

0.621

Sameness Quotient

The Sameness Quotient is a score between 0 and 1, indicating the proportion of differences in the heteromorphic profile, against the maximum possible for a cardinality. A higher quotient indicates a less complex scale, whereas a quotient of 0 indicates a scale with maximum complexity.

0.583

Generator

This scale has a generator of 1, originating on 9.

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}242
A{9,1,4}341.8
A♯{10,2,5}352.2
Minor Triadsdm{2,5,9}242
am{9,0,4}352.2
a♯m{10,1,5}341.8
Augmented TriadsC♯+{1,5,9}431.6
Diminished Triads{9,0,3}163
a♯°{10,1,4}232
{11,2,5}163
Parsimonious Voice Leading Between Common Triads of Scale 3647. Created by Ian Ring ©2019 C#+ C#+ dm dm C#+->dm F F C#+->F A A C#+->A a#m a#m C#+->a#m A# A# dm->A# am am F->am a°->am am->A a#° a#° A->a#° a#°->a#m a#m->A# A#->b°

view full size

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.

Diameter6
Radius3
Self-Centeredno
Central VerticesC♯+, a♯°
Peripheral Verticesa°, b°

Modes

Modes are the rotational transformation of this scale. Scale 3647 can be rotated to make 8 other scales. The 1st mode is itself.

2nd mode:
Scale 3871
Scale 3871: Nonatonic Chromatic 5, Ian Ring Music TheoryNonatonic Chromatic 5
3rd mode:
Scale 3983
Scale 3983: Nonatonic Chromatic 6, Ian Ring Music TheoryNonatonic Chromatic 6
4th mode:
Scale 4039
Scale 4039: Nonatonic Chromatic 7, Ian Ring Music TheoryNonatonic Chromatic 7
5th mode:
Scale 4067
Scale 4067: Nonatonic Chromatic 8, Ian Ring Music TheoryNonatonic Chromatic 8
6th mode:
Scale 4081
Scale 4081: Nonatonic Chromatic Descending, Ian Ring Music TheoryNonatonic Chromatic Descending
7th mode:
Scale 511
Scale 511: Chromatic Nonamode, Ian Ring Music TheoryChromatic NonamodeThis is the prime mode
8th mode:
Scale 2303
Scale 2303: Nonatonic Chromatic 2, Ian Ring Music TheoryNonatonic Chromatic 2
9th mode:
Scale 3199
Scale 3199: Nonatonic Chromatic 3, Ian Ring Music TheoryNonatonic Chromatic 3

Prime

The prime form of this scale is Scale 511

Scale 511Scale 511: Chromatic Nonamode, Ian Ring Music TheoryChromatic Nonamode

Complement

The enneatonic modal family [3647, 3871, 3983, 4039, 4067, 4081, 511, 2303, 3199] (Forte: 9-1) is the complement of the tritonic modal family [7, 2051, 3073] (Forte: 3-1)

Inverse

The inverse of a scale is a reflection using the root as its axis. The inverse of 3647 is 3983

Scale 3983Scale 3983: Nonatonic Chromatic 6, Ian Ring Music TheoryNonatonic Chromatic 6

Interval Matrix

Each row is a generic interval, cells contain the specific size of each generic. Useful for identifying contradictions and ambiguities.

Contradictions (140)

Ambiguities(35)

Hierarchizability

Based on the work of Niels Verosky, hierarchizability is the measure of repeated patterns with "place-finding" remainder bits, applied recursively to the binary representation of a scale. For a full explanation, read Niels' paper, Hierarchizability as a Predictor of Scale Candidacy. The variable k is the maximum number of remainders allowed at each level of recursion, for them to count as an increment of hierarchizability. A high hierarchizability score is a good indicator of scale candidacy, ie a measure of usefulness for producing pleasing music. There is a strong correlation between scales with maximal hierarchizability and scales that are in popular use in a variety of world musical traditions.

kHierarchizabilityBreakdown PatternDiagram
111111110001113647k = 1h = 1
211111110001113647k = 2h = 1
32(111)(111)000(111)3647k = 3h = 2
42(1111)1000(1111)3647k = 4h = 2
52(1111)1000(1111)3647k = 5h = 2

Center of Gravity

If tones of the scale are imagined as identical physical objects spaced around a unit circle, the center of gravity is the point where the scale is balanced.

Position

with origin in the center

(0.151781, -0.262892)
Distance from Center0.303562
Angle in degrees

measured clockwise starting from the root.

30
Angle in cents

100 cents = 1 semitone.

100

Transformations:

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. A note about the multipliers: multiplying by 1 changes nothing, multiplying by 11 produces the same result as inversion. 5 is the only non-degenerate multiplier, with the multiplier 7 producing the inverse of 5.

Abbrev Operation Result Abbrev Operation Result
T0 <1,0> 3647       T0I <11,0> 3983
T1 <1,1> 3199      T1I <11,1> 3871
T2 <1,2> 2303      T2I <11,2> 3647
T3 <1,3> 511      T3I <11,3> 3199
T4 <1,4> 1022      T4I <11,4> 2303
T5 <1,5> 2044      T5I <11,5> 511
T6 <1,6> 4088      T6I <11,6> 1022
T7 <1,7> 4081      T7I <11,7> 2044
T8 <1,8> 4067      T8I <11,8> 4088
T9 <1,9> 4039      T9I <11,9> 4081
T10 <1,10> 3983      T10I <11,10> 4067
T11 <1,11> 3871      T11I <11,11> 4039
Abbrev Operation Result Abbrev Operation Result
T0M <5,0> 1967      T0MI <7,0> 3773
T1M <5,1> 3934      T1MI <7,1> 3451
T2M <5,2> 3773      T2MI <7,2> 2807
T3M <5,3> 3451      T3MI <7,3> 1519
T4M <5,4> 2807      T4MI <7,4> 3038
T5M <5,5> 1519      T5MI <7,5> 1981
T6M <5,6> 3038      T6MI <7,6> 3962
T7M <5,7> 1981      T7MI <7,7> 3829
T8M <5,8> 3962      T8MI <7,8> 3563
T9M <5,9> 3829      T9MI <7,9> 3031
T10M <5,10> 3563      T10MI <7,10> 1967
T11M <5,11> 3031      T11MI <7,11> 3934

The transformations that map this set to itself are: T0, T2I

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.


This scale analysis was created by Ian Ring, Canadian Composer of works for Piano, and total music theory nerd. Scale notation generated by VexFlow and Lilypond, graph visualization by Graphviz, audio by TiMIDIty and FFMPEG. All other diagrams and visualizations are © Ian Ring. Some scale names used on this and other pages are ©2005 William Zeitler (http://allthescales.org) used with permission.

Pitch spelling algorithm employed here is adapted from a method by Uzay Bora, Baris Tekin Tezel, and Alper Vahaplar. (DOI, Patent owner: Dokuz Eylül University, Used with Permission.

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 naming the Carnatic ragas. Thanks to Niels Verosky for collaborating on the Hierarchizability diagrams. Thanks to u/howaboot for inventing the Center of Gravity metrics.