User:Cmloegcmluin/APS

Revision as of 09:25, 14 October 2023 by FloraC (talk | contribs) (Equal multiplication isn't an "other tuning". This *is* equal multiplication. Also adopt a stricter def for "equal temperament")

An APS, or arithmetic pitch sequence, is a kind of arithmetic and harmonotonic tuning. It can also be called an equal multiplication.

Specification

Its full specification is (n-)APS-p: (n pitches of an) arithmetic pitch sequence adding by interval p. The n is optional. If not provided, the sequence is open-ended.

Formula

The pitch of the k-th step of an APS-p is quite simply kp.

Relationship to other tunings

Vs. rank-1 temperaments

By applying a mapping, APS-p becomes an equal temperament with generator p.

Vs. EPD

If specified, an APS will be equivalent to one period of some EPD, or equal pitch division. Specifically, n-EPD-x = n-APS(x/n), for example 12-EPD1200¢ = 12-APS(1200¢/12) = 12-APS100¢.

Vs. AS

The only difference between an APS and an AS (ambitonal sequence) is that the p for an AS must be rational.

Examples

Example: APS⁴√2 ≈ APS1.189 = 4-EDO = rank-1 temperament w/ generator 300¢ = equal multiplication of 300¢
Quantity (0) 1 2 3 4
Frequency (f) (1) 1.19 1.41 1.68 2
Pitch (log₂f) (2⁰⸍⁴) 2¹⸍⁴ 2²⸍⁴ 2³⸍⁴ 2⁴⸍⁴
Length (1/f) (1) 0.84 0.71 0.59 0.5