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# Scale 455: "Messiaen Mode 5 Rotation 2" ### 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

Messiaen
Messiaen Mode 5 Rotation 2
Western Modern
Two-semitone Tritone Scale
Zeitler
Dozenal
STOian

## Analysis

#### Cardinality

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

{0,1,2,6,7,8}

#### Forte Number

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

6-7

#### 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.

[1, 4]

#### 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.

4 (multihemitonic)

#### Cohemitonia

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

2 (dicohemitonic)

#### 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.

2

#### Modes

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.

2

#### Prime Form

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

yes

#### Generator

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

none

#### 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, 4, 1, 1, 4]

#### 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, 2, 0, 2, 4, 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.

<0.8, 0.333, 0, 0, 0.8, 1>

#### Interval Spectrum

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

p4m2s2d4t3

#### 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> = {6}
<4> = {7,10}
<5> = {8,11}

#### Spectra Variation

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

2

#### 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.

1.866

#### Polygon Perimeter

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

5.535

#### Myhill Property

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

no

#### Balanced

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.

yes

#### 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.

[2,8]

#### 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.

(8, 0, 32)

#### 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.

0.877

#### 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.

0.573

## Generator

This scale has no generator.

There are no common triads (major, minor, augmented and diminished) that can be formed using notes in this scale.

## Modes

Modes are the rotational transformation of this scale. Scale 455 can be rotated to make 2 other scales. The 1st mode is itself.

 2nd mode:Scale 2275 Messiaen Mode 5 3rd mode:Scale 3185 Messiaen Mode 5 Rotation 1

## Prime

This is the prime form of this scale.

## Complement

The hexatonic modal family [455, 2275, 3185] (Forte: 6-7) is the complement of the hexatonic modal family [455, 2275, 3185] (Forte: 6-7)

## Inverse

The inverse of a scale is a reflection using the root as its axis. The inverse of 455 is 3185

 Scale 3185 Messiaen Mode 5 Rotation 1

## 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

Abbrev Operation Result Abbrev Operation Result
T0 <1,0> 455       T0I <11,0> 3185
T1 <1,1> 910      T1I <11,1> 2275
T2 <1,2> 1820      T2I <11,2> 455
T3 <1,3> 3640      T3I <11,3> 910
T4 <1,4> 3185      T4I <11,4> 1820
T5 <1,5> 2275      T5I <11,5> 3640
T6 <1,6> 455       T6I <11,6> 3185
T7 <1,7> 910      T7I <11,7> 2275
T8 <1,8> 1820      T8I <11,8> 455
T9 <1,9> 3640      T9I <11,9> 910
T10 <1,10> 3185      T10I <11,10> 1820
T11 <1,11> 2275      T11I <11,11> 3640
Abbrev Operation Result Abbrev Operation Result
T0M <5,0> 3185      T0MI <7,0> 455
T1M <5,1> 2275      T1MI <7,1> 910
T2M <5,2> 455       T2MI <7,2> 1820
T3M <5,3> 910      T3MI <7,3> 3640
T4M <5,4> 1820      T4MI <7,4> 3185
T5M <5,5> 3640      T5MI <7,5> 2275
T6M <5,6> 3185      T6MI <7,6> 455
T7M <5,7> 2275      T7MI <7,7> 910
T8M <5,8> 455       T8MI <7,8> 1820
T9M <5,9> 910      T9MI <7,9> 3640
T10M <5,10> 1820      T10MI <7,10> 3185
T11M <5,11> 3640      T11MI <7,11> 2275

The transformations that map this set to itself are: T0, T6, T2I, T8I, T2M, T8M, T0MI, T6MI

## 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 453 Raditonic Scale 451 Raga Saugandhini Scale 459 Zaptimic Scale 463 Zythian Scale 471 Dodian Scale 487 Dynian Scale 391 CIYian Scale 423 Sogimic Scale 327 Syptitonic Scale 199 Raga Nabhomani Scale 711 Raga Chandrajyoti Scale 967 Mela Salaga Scale 1479 Mela Jalarnava Scale 2503 Mela Jhalavarali

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. (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.