Canonical extension: Difference between revisions

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Consider a regular temperament on a JI group. The following are both informal concepts.
Consider a regular temperament on a JI group. The following are both informal concepts.
* A strong [[extension]] of said temperament on a JI group with one additional prime is '''natural''' if the commas tempered out by the temperament induce the presence of the added prime.
* A strong [[extension]] of said temperament on a larger JI group is '''natural''' if the commas tempered out by the temperament induce the presence of the added prime(s).
* Such an extension is (more weakly) '''canonical''' if it is the most efficient (accurate and low-complexity) strong extension of the temperament to the larger subgroup.
* Such an extension is (more weakly) '''canonical''' if it is the most efficient (accurate and low-complexity) strong extension of the temperament to the larger subgroup.


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* 5-limit Kleismic -> 2.3.5.13 Kleismic
* 5-limit Kleismic -> 2.3.5.13 Kleismic
* 5-limit Porcupine -> 2.3.5.11 Porcupine
* 5-limit Porcupine -> 2.3.5.11 Porcupine
<!--* 5-limit Wurschmidt -> 2.3.5.23 Wurschmidt-->
* 5-limit Wurschmidt -> 2.3.5.23.47.49 Wurschmidt


=== Canonical but non-natural extensions ===
=== Canonical but non-natural extensions ===
* 5-limit Meantone -> 7-limit Septimal Meantone (12 & 19)
* 5-limit Meantone -> 7-limit Septimal Meantone (12 & 19)
* 5-limit Tetracot -> 2.3.5.13 Tetracot
* 5-limit Tetracot -> 2.3.5.13 Tetracot

Revision as of 15:00, 4 February 2026

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This is a technical or mathematical page. While the subject may be of some relevance to music, the page treats the subject in technical language.

Consider a regular temperament on a JI group. The following are both informal concepts.

  • A strong extension of said temperament on a larger JI group is natural if the commas tempered out by the temperament induce the presence of the added prime(s).
  • Such an extension is (more weakly) canonical if it is the most efficient (accurate and low-complexity) strong extension of the temperament to the larger subgroup.

Examples

Natural extensions

  • 5-limit Kleismic -> 2.3.5.13 Kleismic
  • 5-limit Porcupine -> 2.3.5.11 Porcupine
  • 5-limit Wurschmidt -> 2.3.5.23.47.49 Wurschmidt

Canonical but non-natural extensions

  • 5-limit Meantone -> 7-limit Septimal Meantone (12 & 19)
  • 5-limit Tetracot -> 2.3.5.13 Tetracot