innocuous-symmetry/procedural-drones-01
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working on logic for melodic coherence

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This commit is contained in:
Mikayla Dobson
2022-05-13 09:28:00 -05:00
parent 7c1619c3c1
commit b6d881a299
1 changed files with 37 additions and 6 deletions
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43
src/pitch_generation/melodicGeneration.js
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@@ -1,7 +1,7 @@
import { getRandomPitches } from './getRandomPitches.js';
import { extractPitchName } from '../data_conversions/extractPitchName.js';
import { extractOctave } from '../data_conversions/extractOctave.js';
import { musicalPitches } from '../harmonyUtil.js';
import { musicalPitches, pitchsets } from '../harmonyUtil.js';
// reads the pitch of the previous sonority and determines appropriate melodic movement for the soprano
// returns a boolean which triggers a recursive call if the interval received is out of expected values
@@ -9,15 +9,18 @@ import { musicalPitches } from '../harmonyUtil.js';
let callCount = 0;
export const melodicGeneration = (prevPitches) => {
console.clear();
callCount++;
// direction: boolean; true refers to ascending motion; false refers to descending motion
let direction;
const preferredMotion = [0,1,2,3,4];
let isMelodic = true;
const preferredMotion = [0,1,2,3,4,12];
const sopranoLength = pitchsets[3].length;
let newPitches = getRandomPitches();
let prevSoprano = prevPitches[3];
let newSoprano = newPitches[3];
@@ -27,16 +30,44 @@ export const melodicGeneration = (prevPitches) => {
let pitchNameOne = extractPitchName(prevSoprano);
let pitchNameTwo = extractPitchName(newSoprano);
// 3 is added here to account for the octave wrap associated with octave wrap as the number in pitch
// notation shifts; i.e. B4 to C5 being only a semitone, despite the octave marker completely changing
let pitchNumOne = musicalPitches.indexOf(pitchNameOne);
let pitchNumTwo = musicalPitches.indexOf(pitchNameTwo);
console.log(prevSoprano, newSoprano);
let interval = pitchNumOne - pitchNumTwo;
let interval = pitchNumTwo - pitchNumOne;
direction = interval > 0;
if (octaveOne === octaveTwo) console.log("OCTAVE: same");
if (octaveOne > octaveTwo) {
console.log('OCTAVE: first is higher');
if ((pitchNumTwo + 3) % 12 <= (pitchNumOne + 3) % 12) {
console.log('CAUGHT OCTAVE SHIFT');
console.log(interval);
interval = Math.abs(interval) * -1;
}
console.log(interval);
// interval = 12 - interval;
} else if (octaveOne < octaveTwo) {
console.log('OCTAVE: second is higher');
console.log(`pre shift: ${interval}`);
if (interval < pitchNumOne) (interval = 12 + Math.abs(interval));
console.log(`post shift: ${interval}`);
}
// this boolean evaluates first, but may be changed to false pending the following conditional flow
isMelodic = preferredMotion.includes(Math.abs(interval));
// edge case: does not allow augmented triads to be considered "consonant"
if ((pitchNameOne === 'F#' || pitchNameTwo === 'Bb') && (pitchNameOne === 'Bb' || pitchNameTwo === 'F#')) {
isMelodic = false;
}
console.log(prevSoprano, newSoprano);
console.log(pitchNumOne, pitchNumTwo);
console.log(`interval: ${interval}`);
console.log(`direction: ${direction ? 'ascending' : 'descending'}`);
console.log(`isMelodic: ${isMelodic}`);