Cross-set scale: Difference between revisions

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Cited Narushima's book which apparently attributes the term "cross-set" to Wilson.
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In combinatorics, this operation is called a [[wikipedia:Sumset|sumset]].
In combinatorics, this operation is called a [[wikipedia:Sumset|sumset]].


As reported by [[Nick Vuci]], "the term Cross-Set as applied to scales is apparently the invention of Praveen Venkataramana".
The term ''cross-set'' goes back to [[Erv Wilson]].<ref name="Narushima 2017">Narushima, T. (2017). Microtonality and the tuning systems of Erv Wilson. Routledge.</ref>
 
== Examples ==
== Examples ==
The 4:5:6:7 cross-set scale is generated by multiplying every pair of intervals from the 4:5:6:7 tetrad ([[1/1]] - [[5/4]] - [[3/2]] - [[7/4]]), including an interval with itself, and [[Octave reduction|octave-reducing]] as necessary. It contains 10 distinct pitches out of 16 combinations.
The 4:5:6:7 cross-set scale is generated by multiplying every pair of intervals from the 4:5:6:7 tetrad ([[1/1]] - [[5/4]] - [[3/2]] - [[7/4]]), including an interval with itself, and [[Octave reduction|octave-reducing]] as necessary. It contains 10 distinct pitches out of 16 combinations.
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== See also ==
== See also ==
* [[Tonality diamond]]
* [[Tonality diamond]]
== References ==


[[Category:Scale]]
[[Category:Scale]]

Revision as of 18:20, 24 July 2023

A cross-set scale is a scale generated by taking every ordered pair in the Cartesian product of two or more scales, or of a scale with itself, and stacking all elements in each ordered pair. In mathematical notation, the cross-set of scales A, B, ..., Z is (note that stacking has been written as addition):

[math]\displaystyle{ \text{Cross-set}(A, B, ..., Z) = \{ a + b + \cdots + z : (a, b, ..., z) \in A \times B \times \cdots \times Z\}. }[/math]

In combinatorics, this operation is called a sumset.

The term cross-set goes back to Erv Wilson.[1]

Examples

The 4:5:6:7 cross-set scale is generated by multiplying every pair of intervals from the 4:5:6:7 tetrad (1/1 - 5/4 - 3/2 - 7/4), including an interval with itself, and octave-reducing as necessary. It contains 10 distinct pitches out of 16 combinations.

1/1 × 1/1
1/1
5/4 × 1/1
5/4
3/2 × 1/1
3/2
7/4 × 1/1
7/4
1/1 × 5/4
5/4
5/4 × 5/4
25/16
3/2 × 5/4
15/8
7/4 × 5/4
35/32
1/1 × 3/2
3/2
5/4 × 3/2
15/8
3/2 × 3/2
9/8
7/4 × 3/2
21/16
1/1 × 7/4
7/4
5/4 × 7/4
35/32
3/2 × 7/4
21/16
7/4 × 7/4
49/32

The starting scales do not need to be in just intonation; a cross-set scale could be constructed from any kind of scale.

Music

4:5:6:7 cross-set tuning

Nick Vuci
Frédéric Gagné

See also

References

  1. Narushima, T. (2017). Microtonality and the tuning systems of Erv Wilson. Routledge.