Oneirotonic

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The term oneirotonic (/oʊnaɪrəˈtɒnɪk/ oh-ny-rə-TON-ik or /ənaɪrə-/ ə-ny-rə-) is used for the 8-note MOS structure 5L 3s, whose brightest mode is LLsLLsLs. The name "oneirotonic" was coined by Cryptic Ruse after the Dreamlands in H.P. Lovecraft's Dream Cycle mythos. Oneirotonic is a distorted diatonic, because it has one extra small step compared to diatonic (5L 2s).

The generator size ranges from 450¢ (3\8) to 480¢ (2\5). Hence any edo with an interval between 450¢ and 480¢ has an oneirotonic scale.

In terms of regular temperaments, there are at least two melodically viable ways to interpret oneirotonic:

  1. When the generator is between 461.54¢ (5\13) and 466.67¢ (7\18): A-Team (13&18, a 4:5:9:21 or 2.9.5.21 temperament)
  2. When the generator is between 457.14¢ (8\21) and 461.54¢ (5\13): Petrtri (13&21, a 4:5:9:11:13:17 or 2.5.9.11.13.17 temperament)

Notation

The notation used in this article is LLsLLsLs = JKLMNOPQJ (with J ≈ 180 Hz), unless specified otherwise.

Intervals

Generators Notation (1/1 = J) Octatonic interval category name Generators Notation of 2/1 inverse Octatonic interval category name
The "diatonic" 8-note scale has the following intervals (from some root):
0 J perfect unison 0 J octave
1 M perfect mosfourth -1 Ob perfect mossixth
2 P major mosseventh -2 Lb minor mosthird
3 K major mossecond -3 Qb minor moseighth
4 N major mosfifth -4 Nb minor mosfifth
5 Q major moseighth -5 Kb minor mossecond
6 L major mosthird -6 Pb minor mosseventh
7 O augmented sixth -7 Mb diminished fourth
The "chromatic" 13-note scale also has the following intervals (from some root):
8 J# augmented unison -8 Jb diminished octave
9 M# augmented mosfourth -9 Obb diminished mossixth
10 P# augmented mosseventh -10 Lbb diminished mosthird
11 K# augmented mossecond -11 Qbb diminished moseighth
12 N# augmented mosfifth -12 Nbb diminished mosfifth

Modal harmony

Oneirotonic modes are named after cities in the Dreamlands.

  1. Dylathian: LLsLLsLs (major with hints of Mixolydian and "#5")
  2. Ilarnekian: LLsLsLLs (major with hints of "b6")
  3. Celephaïsian: LsLLsLLs (the oneirotonic melodic minor. Very classical-sounding; Easley Blackwood's 13-note etude uses this as its home mode.)
  4. Ultharian: LsLLsLsL (A Dorian analogue. Another Dorian analogue is the MODMOS LsLLLsLs)
  5. Mnarian: LsLsLLsL
  6. Kadathian: sLLsLLsL (another "Locrian")
  7. Hlanithian: sLLsLsLL (closest Locrian analogue)
  8. Sarnathian: sLsLLsLL (Darkest but ironically the most consonant. Here be dragons.)

The modes in 13edo edo steps and C-H notation:

Oneirotonic.png

Modes with sharp tritone

At least in A-Team, the brighter modes can be viewed as providing a distorted version of diatonic functional harmony. For example, in the Dylathian mode, the 4:5:9 triad on the sixth degree can sound like both "V" and "III of iv" depending on context. Basic chord progressions can move by minor fourths, thirds, or major seconds: for example, J major-M minor-P minor-Ob major-J major (in Ilarnekian) or J major-K major-O major-M major-J major (in Dylathian).

Modes with flat tritone

The darker modes are radically different in character than the brighter modes. Because of the consonant 11/8 minor tritone and the 13/8 minor sixth, the flat tritone sounds more like a stable scale function.

A-Team (13&18, 4:5:9:(11:13):21) interpretation

The sizes of the generator, large step and small step of oneirotonic are as follows in various edos:

13edo 18edo 31edo 64/49 generator JI intervals represented (2.9.5.21 subgroup)
generator 5\13, 461.54 7\18, 466.67 12\31, 464.52 462.35 21/16
L 2\13, 184.62 3\18, 200.00 5\31, 193.55 187.04 9/8, 10/9
s 1\13, 92.31 1\18, 66.66 2\31, 77.42 88.26 21/20

Intervals

Sortable table of Dylathian, the brightest mode:

Degree Size in 13edo Size in 18edo Size in 31edo Note name on J Approximate ratios[1] #Gens up
1 0\13, 0.00 0\18, 0.00 0\31, 0.00 J 1/1 0
2 2\13, 184.62 3\18, 200.00 5\31, 193.55 K 9/8, 10/9 +3
3 4\13, 369.23 6\18, 400.00 10\31, 387.10 L 5/4 +6
4 5\13, 461.54 7\18, 466.67 12\31, 464.52 M 21/16, 13/10 +1
5 7\13, 646.15 10\18, 666.66 17\31, 658.06 N 13/9, 16/11 +4
6 9\13, 830.77 13\18, 866.66 22\31, 851.61 O 13/8, 18/11 +7
7 10\13, 923.08 14\18, 933.33 24\31, 929.03 P 12/7 +2
8 12\13, 1107.69 17\18, 1133.33 29\31, 1122.58 Q +5
  1. The harmonics over 1/1 are in bold. The ratio interpretations that are not valid for 18edo are italicized.

Chords

Despite being melodically familiar, oneirotonic is harmonically complex in that it doesn't represent many lower-complexity JI triads other than 4:9:21, 9:10:13, and the occasional 4:5:9. Hence oneirotonic may especially benefit from either using inharmonic timbres in addition to harmonic ones or using a well-tempered version of 13edo adopted for this scale. The availability of certain consonances also varies greatly by mode: for example, only Dylathian, Ilarnekian and Sarnathian have a 5/4 on the tonic, and only Mnarian, Kadathian, Hlanithian and Sarnathian have an 11/8 on the tonic.

Petrtri (13&21, 4:5:9:11:13:17) interpretation

The sizes of the generator, large step and small step of oneirotonic are as follows in various tunings. (Golden oneirotonic uses 1200*(2-φ) = 458.3592135¢ as generator and has L/s = φ; it is the limit of Fibonacci number edos 13, 21, 34, 55, 89,... in oneirotonic tunings.)

13edo 21edo 34edo Golden oneirotonic JI intervals represented (2.5.9.11.13.17 subgroup)
generator 5\13, 461.54 8\21, 457.14 13\34, 458.82 458.36 13/10, 17/13, 22/17
L 2\13, 184.62 3\21, 171.43 5\34, 176.47 175.08 10/9, 11/10
s 1\13, 92.31 2\21, 114.29 3\34, 105.88 108.20 18/17, 17/16

Intervals

Sortable table of Dylathian, the brightest mode:

Degree Size in 13edo Size in 21edo Size in 34edo Note name on J Approximate ratios #Gens up
1 0\13, 0.00 0\21, 0.00 0\34, 0.00 J 1/1 0
2 2\13, 184.62 3\21, 171.43 5\34, 176.47 K 10/9, 11/10 +3
3 4\13, 369.23 6\21, 342.86 10\34, 352.94 L 11/9, 16/13 +6
4 5\13, 461.54 8\21, 457.14 13\34, 458.82 M 13/10, 17/13, 22/17 +1
5 7\13, 646.15 11\21, 628.57 18\34, 635.294 N 13/9, 16/11 +4
6 9\13, 830.77 14\21, 800.00 23\34, 811.77 O 8/5 +7
7 10\13, 923.08 16\21, 914.29 26\34, 917.65 P 17/10 +2
8 12\13, 1107.69 19\21, 1085.71 31\34, 1094.12 Q 17/9, 32/17 +5


Chords

The pentad P1-m8-M10-m12-M16 "5:9:11:13:17" occurs twice in the 8 note mos of 13edo and 21edo's father[8]. The pentad P1-M3-M4-m6-m9 "4:5:11:13:17" occurs once.

Triad occurrences:

  • P1-M2-M3 "9:10:11" occurs 2x
  • P1-M2-M5 "9:10:13" occurs 3x
  • P1-M2-M8 "9:10:17" occurs 3x
  • P1-M3-M5 "9:11:13" occurs 2x
  • P1-M3-M8 "9:11:17" occurs 2x
  • P1-M5-M8 "9:13:17" occurs 3x

All 8 modes provide chords in various prime families (list of modes is non-exhaustive):

  • /2 chords occur on Sarnathian
  • /5 chords occur on Ultharian and Mnarian
  • /9 chords occur on Dylathian and Ilarnekian
  • /11 chords occur on Hlanithian and Sarnathian
  • /13 chords occur on Mnarian and Kadathian
  • /17 chords occur on Hlanithian and Kadathian

Samples

‎(A rather classical-sounding 3-part harmonization of the ascending J Ilarnekian scale; tuning is 13edo)

(13edo, first 30 seconds is in Celephaïsian mode)

(13edo, Ilarnekian)

(by Igliashon Jones, 13edo)