05Constrain first, vary second

Melody & arps

A useful generator does not choose from every pitch equally. It lands on chord tones, travels through the scale and uses chromatic notes only as short approaches.

Minor scale · travel0 2 3 5 7 8 10

0root1·223♭34·546·758♭69·10♭711·

Minor 7 · land0 3 7 10

0root1·2·3♭34·5·6·758·9·10♭711·

Passing tones2 5 8

0·1·223·4·546·7·8♭69·10·11·

Chromatic tension1 6 11

0·1♭22·3·4·5·6♭5 / ♯47·8·9·10·117

Arpeggio shapes

Motion	Offsets	Use
minor pulse	`0 3 7 3`	small, stable loop
minor 7 up	`0 3 7 10`	clear chord outline
skip	`0 7 3 10`	less scale-like
pendulum	`0 7 3 10 3 7`	balanced back-and-forth
up / down	`0 3 7 10 7 3`	continuous contour
octave spread	`0 7 15 10`	`15 = 12 + 3`
octave jumps	`0 12 3 15 7 19`	wide synth arp

Generator rule

strong beatchoose(CHORD)[0 3 7 10] makes the harmony legible.

between beatschoose(SCALE)[0 2 3 5 7 8 10] connects the anchors.

Example line0 → 2 → 3 → 7 → 10 → 8 → 7 → 5

0land

2pass

3land

7land

10land

8pass

7land

5pass

Approach, phrase, mutate

Approach the fifth6 → 7

Approach the fifth8 → 7

Approach the root above11 → 12

Approach the root below1 → 0

recognizable phraseA · 0 3 7 10A · 0 3 7 10B · 7 5 3 2A · 0 3 7 10

one mutation / 4–8 bars0 3 7 100 3 8 100 5 8 10

Choice	Start probability	Meaning
chord tone	`70%`	identity
scale tone	`25%`	connection
chromatic	`5%`	brief friction