Constant structure: Difference between revisions
clarified and expanded diatonic scale example and interval matrix discussion |
note the practical significance of CS for isomorphic instruments |
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A [[scale]] is said to have '''constant structure''' ('''CS''') if its [[interval class]]es are distinct. That is, each [[interval size]] that occurs in the scale always [[subtend]]s the same number of scale steps. This means that you never get something like an interval being counted as a fourth one place, and a fifth another place. | A [[scale]] is said to have '''constant structure''' ('''CS''') if its [[interval class]]es are distinct. That is, each [[interval size]] that occurs in the scale always [[subtend]]s the same number of scale steps. This means that you never get something like an interval being counted as a fourth one place, and a fifth another place. | ||
If a scale has constant structure, that scale can be mapped to an [[isomorphic keyboard]] or similar isomorphic instrument such that each chord with the same interval structure can be played using the same fingering shape. | |||
The term "constant structure" was coined by [[Erv Wilson]]. In academic music theory, constant structure is called the partitioning property, but Erv got there first. | The term "constant structure" was coined by [[Erv Wilson]]. In academic music theory, constant structure is called the partitioning property, but Erv got there first. | ||