mardi 2 janvier 2018

Twelve Tone Rows with Dual Properties

Music Theory ---> 12-tone theory


This is a study of some 12-tone rows. The basic idea is to take a big list of series that were collected for having a property of loose self-similarity (because of how they were generated) and to test those series when rotated for a different definition of self-similarity. The best finds will be series with "dual citizenship".

Series are generated as truncated power-residue index series. As such, they will all possess loose self-similarity of the first 6 notes.

An example with 3 ^ n mod 17:

Base: 3 Mod: 17 Period: 16
-----------------------------------------------------------
Power: 1 2 3 4 5 6 7 8 9 10 11 12
-----------------------------------------------------------
Raw: 16 14 1 12 5 15 11 10 2 3 7 13
Rank: 11 9 0 7 3 10 6 5 1 2 4 8
-----------------------------------------------------------
Mod 11: 5 3 1 1 5 4 0 10 2 3 7 2
Mod 12: 4 2 1 0 5 3 11 10 2 3 7 1
Mod 13: 3 1 1 12 5 2 11 10 2 3 7 0



When truncated and ranked, the 12-tone series becomes B,A,C,G,Eb,Bb,F#,F,C#,D,E,G#.

displaying in an "every other" permutation square:

Code:

B,  A,  C,  G,  Eb, Bb, Gb, F,  Db, D,  E,  Ab
A,  G,  Bb, F,  D,  Ab, B,  C,  Eb, Gb, Db, E
G,  F,  Ab, C,  Gb, E,  A,  Bb, D,  B,  Eb, Db
F,  C,  E,  Bb, B,  Db, G,  Ab, Gb, A,  D,  Eb
C,  Bb, Db, Ab, A,  Eb, F,  E,  B,  G,  Gb, D
Bb, Ab, Eb, E,  G,  D,  C,  Db, A,  F,  B,  Gb
Ab, E,  D,  Db, F,  Gb, Bb, Eb, G,  C,  A,  B
E,  Db, Gb, Eb, C,  B,  Ab, D,  F,  Bb, G,  A
Db, Eb, B,  D,  Bb, A,  E,  Gb, C,  Ab, F,  G
Eb, D,  A,  Gb, Ab, G,  Db, B,  Bb, E,  C,  F
D,  Gb, G,  B,  E,  F,  Eb, A,  Ab, Db, Bb, C
Gb, B,  F,  A,  Db, C,  D,  G,  E,  Eb, Ab, Bb

The loose partial self-similarity can be quantified by noting the intervals of the colums: 10,10,10,7,10,10,8,9,2,11,4,5.

A series derived from taking every other note from some positions of this series will resemble the original series, so this can be used musically and perceived -- it's not hard to hear.

Every truncated ranked power-residue index series will have some of this self-similarity. A list of these series can be built up.

These power-residue series tend to be relatively "musical" because they usually have nice mixtures of intervals and contours.

Then series made from such a list can be tested from starting points other than the first note, to see if any of them also possess self-similarity as defined by the parameters of the Microtonal Scales program. These parameters can be adjusted to only select the series with the most extensive self-similiarty.

The study as I intend it will just be individual dual series, with analysis.

A first example. Unfortunately, I don't know what power-residue series generated it.

(0 10 2 3 6 7 4 1 9 11 5 8)

The first six notes C,Bb,D,Eb,F#,G are the ones passing the second test, and the segment beginning on 4 is the power-res portion: E,C#,A,B,F,Ab

Code:

C,Bb,D,Eb,Gb,G,E,Db,A,B,F,Ab
                                            |
                                            v
C,  Bb, D,  Eb, Gb, G,  E,  Db, A,  B,  F,  Ab
D,  C,  E,  F,  Ab, A,  Gb, Eb, B,  Db, G,  Bb
Bb, Ab, C,  Db, E,  F,  D,  B,  G,  A,  Eb, Gb
A,  G,  B,  C,  Eb, E,  Db, Bb, Gb, Ab, D,  F    ------>
Gb, E,  Ab, A,  C,  Db, Bb, G,  Eb, F,  B,  D
F,  Eb, G,  Ab, B,  C,  A,  Gb, D,  E,  Bb, Db
Ab, Gb, Bb, B,  D,  Eb, C,  A,  F,  G,  Db, E
B,  A,  Db, D,  F,  Gb, Eb, C,  Ab, Bb, E,  G
Eb, Db, F,  Gb, A,  Bb, G,  E,  C,  D,  Ab, B
Db, B,  Eb, E,  G,  Ab, F,  D,  Bb, C,  Gb, A
G,  F,  A,  Bb, Db, D,  B,  Ab, E,  Gb, C,  Eb
E,  D,  Gb, G,  Bb, B,  Ab, F,  Db, Eb, A,  C
                ^
                |



Starting from the seventh note above, tranposed to C,
and displayed in every-other square:


C,  A,  F,  G,  Db, E,  Ab, Gb, Bb, B,  D,  Eb
A,  G,  E,  Gb, B,  Eb, C,  F,  Db, Ab, Bb, D
G,  Gb, Eb, F,  Ab, D,  A,  E,  B,  C,  Db, Bb
Gb, F,  D,  E,  C,  Bb, G,  Eb, Ab, A,  B,  Db
F,  E,  Bb, Eb, A,  Db, Gb, D,  C,  G,  Ab, B
E,  Eb, Db, D,  G,  B,  F,  Bb, A,  Gb, C,  Ab
Eb, D,  B,  Bb, Gb, Ab, E,  Db, G,  F,  A,  C
D,  Bb, Ab, Db, F,  C,  Eb, B,  Gb, E,  G,  A
Bb, Db, C,  B,  E,  A,  D,  Ab, F,  Eb, Gb, G
Db, B,  A,  Ab, Eb, G,  Bb, C,  E,  D,  F,  Gb
B,  Ab, G,  C,  D,  Gb, Db, A,  Eb, Bb, E,  F
Ab, C,  Gb, A,  Bb, F,  B,  G,  D,  Db, Eb, E

9,10,11,11,11,11,11,8,3,10,9,  intervals of columns

The purpose of the thread is to share these special-property rows with anyone else who might be interested in using them. Music is a big tent that allows for all kinds of activities aside from the main ones of composing and performing.


via International Skeptics Forum http://ift.tt/2CqOCcs

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