Fokker block: Difference between revisions
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{{Wikipedia| Fokker periodicity block }} | {{Wikipedia| Fokker periodicity block }} | ||
A '''Fokker block''' (or periodicity block) | A '''Fokker block''' (or periodicity block) is a [[periodic scale|periodic]] constant-structure [[scale]] that can be thought of as a region on a lattice of [[pitch class]]es (of a [[JI subgroup]] or a [[regular temperament]]) shaped as a parellelogram, parellelepiped, or higher-dimensional analog whose vertices fall upon the lattice with one vertex at the origin. A Fokker block comprises those intervals in the lattice which fall inside the parellelepiped or on the faces of the parellelepiped which intersect the origin and no others (or equivalently, those intervals which fall inside the parellelepiped after it is moved a very small amount while keeping the origin inside it). The scale repeats at the [[interval of equivalence]], which lies on the [[1/1|unison]] in the lattice of pitch classes. If the edges of the parellelepiped correspond to intervals which are too large, the Fokker block will not be constant structure and hence a '''weak Fokker block'''. | ||
The concept of the Fokker block was developed by the physicist and music theorist [[Adriaan Fokker]]. | The concept of the Fokker block was developed by the physicist and music theorist [[Adriaan Fokker]]. |