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{{Infobox Regtemp
{{Infobox regtemp
| Title = Ultrapyth
| Title = Ultrapyth
| Subgroups = 2.3.5.7, 2.3.5.7.13
| Subgroups = 2.3.5.7, 2.3.5.7.13
| Comma basis = [[64/63]], [[6860/6561]] (2.3.5.7)<br>[[64/63]], [[91/90]], [[6125/6084]]
| Comma basis = [[64/63]], [[6860/6561]] (2.3.5.7)<br>[[64/63]], [[91/90]], [[6125/6084]] (2.3.5.7.13)
| Edo join 1 = 5 | Edo join 2 = 32
| Edo join 1 = 5 | Edo join 2 = 32
| Mapping = 1; 1 14 -2 18
| Mapping = 1; 1 14 -2 18
| Generator = 3/2
| Generators = 3/2
| Generator tuning = 713.6
| Generators tuning = 713.6
| Optimization method = CWE
| Optimization method = CWE
| MOS scales = [[5L 7s]], [[5L 12s]], [[5L 17s]], [[5L 22s]]
| MOS scales = [[5L 7s]], [[5L 12s]], [[5L 17s]], [[5L 22s]]
| Pergen = (P8, P5)
| Pergen = (P8, P5)
| Odd limit 1 = 7 | Mistuning 1 = 11.4 | Complexity 1 = 17
| Odd limit 1 = 7 | Mistuning 1 = 11.4 | Complexity 1 = 17
| Odd limit 2 = (2.3.5.7.13) 21 | Mistuning 2 = 22.8 | Complexity 2 = 22
| Odd limit 2 = 2.3.5.7.13 21 | Mistuning 2 = 22.8 | Complexity 2 = 22
}}
}}
'''Ultrapyth''' is an alternative [[extension]] of the [[archy]] [[chain of fifths]] to [[superpyth]]. Like superpyth, it is a [[regular temperament|temperament]] generated by a perfect fifth, where stacking two of them reaches the interval of [[8/7]][[~]][[9/8]], tempering out [[64/63]]. The difference is that instead of extending to 2.3.5.7 by mapping 5 to +9 generators, it extends to the 2.3.7.13/5 subgroup (known as '''oceanfront''') by mapping the ultramajor third [[13/10]] to +4 generators (which is also the diatonic major third), tempering out [[91/90]]. This makes sense because the tunings of 2.3.7 archy that optimize for the simplest 2.3.7 intervals (8/7 and [[7/6]]) are sharp of the optimal tuning for 9/7, making that third more ultramajor than supermajor. If intervals of 5 and 13 independently are desired (i.e. [[5/4]], [[13/8]]), then oceanfront may be extended to ultrapyth by mapping 5 to +14 fifths (a double-augmented unison) and 13 to +18 fifths (a double-augmented third). The best tunings for ultrapyth are between 712 and 714 cents.
'''Ultrapyth''' is an alternative [[extension]] of the [[archy]] [[chain of fifths]] to [[superpyth]]. Like superpyth, it is a [[regular temperament|temperament]] generated by a perfect fifth, where stacking two of them reaches the interval of [[8/7]][[~]][[9/8]], tempering out [[64/63]]. The difference is that instead of extending to 2.3.5.7 by mapping 5 to +9 generators, it extends to the 2.3.7.13/5 subgroup (known as '''oceanfront''') by mapping the ultramajor third [[13/10]] to +4 generators (which is also the diatonic major third), tempering out [[91/90]]. This makes sense because the tunings of 2.3.7 archy that optimize for the simplest 2.3.7 intervals (8/7 and [[7/6]]) are sharp of the optimal tuning for 9/7, making that third more ultramajor than supermajor. If intervals of 5 and 13 independently are desired (i.e. [[5/4]], [[13/8]]), then oceanfront may be extended to ultrapyth by mapping 5 to +14 fifths (a double-augmented unison) and 13 to +18 fifths (a double-augmented third). The best tunings for ultrapyth are between 712 and 714 cents.
Line 172: Line 172:
|13/8
|13/8
|713.363
|713.363
|
| 2.3.5.7.13 13- to 21-odd-limit minimax
|-
|-
| '''[[37edo|22\37]]'''
| '''[[37edo|22\37]]'''

Latest revision as of 10:08, 9 February 2026

Ultrapyth
Subgroups 2.3.5.7, 2.3.5.7.13
Comma basis 64/63, 6860/6561 (2.3.5.7)
64/63, 91/90, 6125/6084 (2.3.5.7.13)
Reduced mapping ⟨1; 1 14 -2 18]
ET join 5 & 32
Generators (CWE) ~3/2 = 713.6 ¢
MOS scales 5L 7s, 5L 12s, 5L 17s, 5L 22s
Ploidacot monocot
Pergen (P8, P5)
Minimax error 7-odd-limit: 11.4 ¢;
2.3.5.7.13 21-odd-limit: 22.8 ¢
Target scale size 7-odd-limit: 17 notes;
2.3.5.7.13 21-odd-limit: 22 notes

Ultrapyth is an alternative extension of the archy chain of fifths to superpyth. Like superpyth, it is a temperament generated by a perfect fifth, where stacking two of them reaches the interval of 8/7~9/8, tempering out 64/63. The difference is that instead of extending to 2.3.5.7 by mapping 5 to +9 generators, it extends to the 2.3.7.13/5 subgroup (known as oceanfront) by mapping the ultramajor third 13/10 to +4 generators (which is also the diatonic major third), tempering out 91/90. This makes sense because the tunings of 2.3.7 archy that optimize for the simplest 2.3.7 intervals (8/7 and 7/6) are sharp of the optimal tuning for 9/7, making that third more ultramajor than supermajor. If intervals of 5 and 13 independently are desired (i.e. 5/4, 13/8), then oceanfront may be extended to ultrapyth by mapping 5 to +14 fifths (a double-augmented unison) and 13 to +18 fifths (a double-augmented third). The best tunings for ultrapyth are between 712 and 714 cents.

If intervals of 11 are desired, 14/11 may be mapped to +9 generators, implying 16/11 is (fittingly) mapped to +11 generators and 11/9 is tempered together with 6/5 (a feature common to many systems with sharp fifths).

The oceanfront mos scales take the form of 5L (5n + 2)s, for n up to 7. Most of these scales resemble 5edo. 37edo makes a good tuning of oceanfront or ultrapyth.

Both oceanfront and ultrapyth were named by Mike Battaglia in 2011[1].

For technical data, see The Biosphere #Oceanfront and Archytas clan #Ultrapyth.

Interval chain

Oceanfront (2.3.7.13/5)
# Cents* Approximate ratios
0 0.0 1/1
1 711.7 3/2
2 223.5 8/7, 9/8
3 935.2 12/7, 26/15
4 447.0 9/7, 13/10
5 1158.7 27/14, 39/20
6 670.4 52/35, 72/49
7 182.2 39/35, 54/49

* In 2.3.7.13/5-subgroup CWE tuning,
octave reduced

Ultrapyth
# Cents* Approximate ratios
2.3.5.7.13 subgroup Full 13-limit extensions
Ultrapyth Ultramarine
0 0.0 1/1
1 713.6 3/2
2 227.3 8/7, 9/8
3 940.9 12/7, 26/15
4 454.5 9/7, 13/10
5 1168.1 27/14, 39/20
6 681.8 52/35, 72/49
7 195.4 39/35, 54/49
8 909.0 81/49, 117/70 56/33 22/13
9 422.7 35/27 14/11 33/26
10 1136.3 25/13, 35/18 21/11, 64/33 88/45
11 649.9 35/24, 40/27 16/11 22/15
12 163.5 10/9 12/11 11/10
13 877.2 5/3 18/11 33/20
14 390.8 5/4
15 1104.4 15/8, 40/21, 52/27
16 618.1 10/7, 13/9
17 131.7 13/12, 15/14
18 845.3 13/8

* In 2.3.5.7.13-subgroup CWE tuning, octave reduced

Tunings

7-limit norm-based tunings
Euclidean
Constrained Constrained & skewed Destretched
Tenney CTE: ~3/2 = 713.2179 ¢ CWE: ~3/2 = 713.5430 ¢ POTE: ~3/2 = 713.6509 ¢

Tuning spectrum

Edo
generator
Unchanged interval
(eigenmonzo)
*
Generator (¢) Comments
3/2 701.955 Pythagorean tuning
9/7 708.771
13\22 709.091 22ccff val
7/6 711.043
16\27 711.111 27cf val
19\32 712.500 Lower bound of 7- and 9-odd-limit diamond monotone
15/8 712.551
15/14 712.908
5/4 713.308 7- and 9-odd-limit minimax
13/8 713.363 2.3.5.7.13 13- to 21-odd-limit minimax
22\37 713.514 Lower bound of 2.3.5.7.13 13-odd-limit diamond monotone
2.3.5.7.13 15- and 21-odd-limit diamond monotone (singleton)
13/10 713.553
14/13 713.585
7/5 713.593
13/12 714.034
5/3 714.181
21/13 714.197
25\42 714.286 42f val
21/20 714.369
13/9 714.789
28\47 714.894 47bcff val
9/5 715.200
7/4 715.587
15/13 717.420
3\5 720.000 Upper bound of 7- and 9-odd-limit,
2.3.5.7.13 13-odd-limit diamond monotone
21/16 729.219

* Besides the octave

See also

References