Module equal 

Equal divisions of any interval, not only of the octave. Equal divisions of any interval, not only of the octave.

Plenty of tunings do not repeat at the octave: Bohlen-Pierce divides a twelfth into thirteen and never sounds an octave, and Carlos’s Alpha, Beta and Gamma repeat at nothing in particular. An EqualDivision divides whatever period it is given, the octave included, and it is what crate::tuningsystem::TuningSystem::Equal holds.

The period is kept as cents so that any interval can be one, and the ratio it came from is kept beside it so the division can still name itself the way the literature does — 13edt rather than 13 equal steps of 1901.955 cents.

use music21_rs::tuningsystem::EqualDivision;

let bohlen_pierce = EqualDivision::tritave(13)?;
assert_eq!(bohlen_pierce.to_string(), "13edt");
assert!((bohlen_pierce.step_cents() - 146.304).abs() < 1e-3);
// Its ninth degree is nowhere near an octave, which is the point of it.
assert!((bohlen_pierce.cents_at(8) - 1170.4).abs() < 0.1);

Structs

EqualDivision

An equal division of an arbitrary interval.

Constants

TRITAVE_CENTS

The tritave, 3/1, in cents — Bohlen-Pierce’s period.