Operations on MOSes: Difference between revisions
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== Sistering == | == Sistering == | ||
'''Sistering''' is the operation of taking a MOS pattern xL ys and reversing the roles of large and small steps, thus creating a yL xs pattern, called the ''sister'' of xL ys. It is called thus because a MOS pattern and its sister share the same MOS as a subset (for example, [[5L 2s]] and [[2L 5s]] both have [[2L 3s]] subsets), thus they share the same parent on the tree of MOS patterns (which corresponds to the [[scale tree]], via taking generator ranges) | '''Sistering''' is the operation of taking a MOS pattern xL ys and reversing the roles of large and small steps, thus creating a yL xs pattern, called the ''sister'' of xL ys. It is called thus because a MOS pattern and its sister share the same MOS as a subset (for example, [[5L 2s]] and [[2L 5s]] both have [[2L 3s]] subsets), thus they share the same parent on the tree of MOS patterns (which corresponds to the [[scale tree]], via taking generator ranges). | ||
If xL ys has a generator range between a\x and b\(x+y) (it always holds that a < b), then its sister yL xs has a generator range between b\(x+y) and (b-a)\y. | If xL ys has a generator range between a\x and b\(x+y) (it always holds that a < b), then its sister yL xs has a generator range between b\(x+y) and (b-a)\y. | ||
Examples: | Examples: | ||
* [[2L 5s]] is the sister of [[5L 2s]] (anti-diatonic). | * [[2L 5s]] is the sister of [[5L 2s]] (and is ofteb called the anti-diatonic). | ||
* [[3L 5s]] is the sister of [[5L 3s]] | * [[3L 5s]] is the sister of [[5L 3s]]. | ||
== Neutralization == | == Neutralization == |