Type Alias ProgressionOptions

The key the degrees are resolved against; a key name such as 'C major' is read as that key.

Which pool of built-in presets to choose from. Ignored when preset names the progression outright.

The meter the bars are counted in, in any form that names one; a meter map is read as the signature it opens in. One chord is laid out per bar, so this is what the chords are spaced by — a chord every three beats in 3/4, every three in 6/8 — and a progression written against another bar length drifts off the bar lines of the part it is played under.

Pick a specific built-in preset by id instead of choosing one by style.

Use this progression rather than a built-in one. Only degrees is required; see BORROWED_DEGREES for the non-diatonic codes.

The generation context.

Its complexity.harmonic sets how much of the progression is replaced by the secondary dominant of what follows: 0 — the default — leaves it alone, 0.5 takes about half of what the voice-leading rules allow, and 1 takes every one of them. Its seed fixes both the preset choice and which chords are replaced, so the same seed always yields the same progression.