Non-over-1 temperament: Difference between revisions

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== Examples ==
== Examples ==
=== Tridec ===
=== Tridec ===
In the broad sense, Tridec can be viewed as any oneirotonic tuning that equates three oneirotonic large steps to a [[4/3]] perfect fourth. [This identification may come in handy since many altered oneirotonic modes have three consecutive large steps.] Based on the JI interpretations of the [[29edo]] and [[37edo]] tunings, it can in fact be viewed as a 2.3.7/5.11/5.13/5 temperament, i.e. a [[Non-over-2 temperament|non-over-2 temperament]] that approximates the chord 5:7:11:13:15. The optimal generator is 455.2178¢, which is very close to 29edo's 11\29 (455.17¢), but we could accept any generator between 17\45 (453.33¢) and 8\21 (457.14¢), if we stipulate that the 3/2 has to be between [[7edo]]'s fifth and [[5edo]]'s fifth.
Tridec is a temperament generated by a generator near 455.2178¢ (for example, [[29edo|11\29]] or [[37edo|14\37]]) and has an 8-note MOS. If you restrict to the 8-note MOS, Tridec is an 2.7/5.11/5.13/5 temperament that tempers the chord 5:7:11:13; one generator represents a 13/10, three generators represent a 11/10, -4 generators represent a 7/5.


Tridec essentially contains all the notes of 2.3.5 [[porcupine]] temperament and satisfies all its relations; hence it is essentially the same as 13-limit [[Ammonite]]; however, provided you restrict yourself to the 8-note MOS, you're using it as a non-over-2 temperament.
Tridec essentially contains all the notes of 2.3.5 [[porcupine]] temperament and satisfies all its relations; hence it is essentially the same as 13-limit [[Ammonite]]; however, provided you restrict yourself to the 8-note MOS, you're using it as a non-over-2 temperament.
The sizes of the generator, large step and small step of oneirotonic are as follows in various tridec tunings.
{| class="wikitable right-2 right-3 right-4 right-5"
|-
!
! [[21edo]]
! [[29edo]]
! [[37edo]]
! Optimal ([[POTE]]) tuning
! JI intervals represented (2.3.7/5.11/5.13/5 subgroup)
|-
| generator (g)
| 8\21, 457.14
| 11\29, 455.17
| 14\37, 454.05
| 455.22
| 13/10
|-
| L (3g - octave)
| 3\21, 171.43
| 4\29, 165.52
| 5\37, 162.16
| 165.65
| 11/10
|-
| s (-5g + 2 octaves)
| 2\21, 114.29
| 3\29, 124.14
| 4\37, 129.73
| 123.91
| 14/13, 15/14
|}


=== Sensi ===
=== Sensi ===

Revision as of 14:13, 7 February 2021

A non-over-2 temperament, or non-/2 temperament, is a regular temperament that tempers a subgroup corresponding to a harmonic series chord r:n1:...:nk where r ≠ 2, but is not meant to approximate a chord of the form 2:m1:...:mk. Non-over-2 temperaments give regular-temperament interpretations to edos that approximate over-2 chords such as 4:5:6:7:11 poorly, such as 14edo, 18edo, 23edo and 29edo.

Examples

Tridec

Tridec is a temperament generated by a generator near 455.2178¢ (for example, 11\29 or 14\37) and has an 8-note MOS. If you restrict to the 8-note MOS, Tridec is an 2.7/5.11/5.13/5 temperament that tempers the chord 5:7:11:13; one generator represents a 13/10, three generators represent a 11/10, -4 generators represent a 7/5.

Tridec essentially contains all the notes of 2.3.5 porcupine temperament and satisfies all its relations; hence it is essentially the same as 13-limit Ammonite; however, provided you restrict yourself to the 8-note MOS, you're using it as a non-over-2 temperament.

Sensi

Sensi is effectively a non-over-2 temperament provided you restrict yourself to the sensi[8] MOS. The sensi[8] MOS only has a 5:6:7:9:13 chord, but no chord of the form 2:m1:...:mk (except 2:3). Thus sensi can be viewed as a 2.6/5.7/5.9/5.13/10 or 2.3.6/5.7/5.13/10 temperament. (See x31eq data page.)

Generators Cents* Approximate ratios
0 0.000 1/1
1 443.322 13/10~9/7
2 886.644 42/25~5/3
3 129.966 13/12~14/13~15/14~27/25
4 573.288 7/5~25/18~18/13
5 1016.610 9/5~70/39
6 259.932 7/6~15/13
7 703.253 3/2
* in 2.3.5.7.13 POTE tuning
2.3.5.7.13 ratio interpretations