Normal forms: Difference between revisions

Normal interval list: clarification
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There is only one normal comma sequence that characterizes septimal meantone. But sometimes a temperament can be characterized by multiple normal comma sequences. However, if a requirement is added that the normal comma sequence be torsion-free, then there is only one characteristic normal comma sequence, and we can speak of ''the'' normal comma sequence of any temperament. For example, both [27/25, 21/20] and [27/25, 49/48] are normal, and they both characterize Beep. But the latter has torsion, so Beep's normal comma sequence is the former.
There is only one normal comma sequence that characterizes septimal meantone. But sometimes a temperament can be characterized by multiple normal comma sequences. However, if a requirement is added that the normal comma sequence be torsion-free, then there is only one characteristic normal comma sequence, and we can speak of ''the'' normal comma sequence of any temperament. For example, both [27/25, 21/20] and [27/25, 49/48] are normal, and they both characterize Beep. But the latter has torsion, so Beep's normal comma sequence is the former.


Normal interval lists can also be used to characterize the [[just intonation subgroups]] on which subgroup temperaments are defined and using which subgroup scales may be constructed. On the pages [[chromatic pairs]], [[subgroup temperaments]] and [[just intonation subgroups]] can be found many examples; the subgroup lists are given in a form where generators of the subgroup are separated by periods so as to flag the fact that the list defines a subgroup. An example would be the Barbados subgroup, 2.3.13/5.
Normal interval lists can also be used to characterize the [[just intonation subgroups]] on which subgroup temperaments are defined and using which subgroup scales may be constructed. On the pages [[chromatic pairs]], [[subgroup temperaments]] and [[just intonation subgroup]]s can be found many examples; the subgroup lists are given in a form where generators of the subgroup are separated by periods so as to flag the fact that the list defines a subgroup. An example would be the Barbados subgroup, 2.3.13/5.
 
In each temperament page on this wiki, however, the "comma lists" are not normal interval lists as defined above. Instead, it shows ratio-wise the simplest comma sequence sufficient to define the temperament.


== Normal val list ==
== Normal val list ==