/**
* music21j -- Javascript reimplementation of Core music21 features.
* music21/voiceLeading -- voiceLeading objects
*
* Copyright (c) 2013-18, Michael Scott Cuthbert and cuthbertLab
* Based on music21, Copyright (c) 2006–18, Michael Scott Cuthbert and cuthbertLab
*
* @namespace music21.voiceLeading
*/
import * as interval from './interval.js';
import * as key from './key.js';
import * as note from './note.js';
import { Music21Object } from './base';
const intervalCache = [];
export const MotionType = {
antiParallel: 'Anti-Parallel',
contrary: 'Contrary',
noMotion: 'No Motion',
oblique: 'Oblique',
parallel: 'Parallel',
similar: 'Similar',
};
/**
* @memberOf music21.voiceLeading
* @extends music21.base.Music21Object
*/
export class VoiceLeadingQuartet extends Music21Object {
constructor(v1n1, v1n2, v2n1, v2n2, analyticKey) {
super();
if (!intervalCache.length) {
intervalCache.push(new interval.Interval('P1'));
intervalCache.push(new interval.Interval('P5'));
intervalCache.push(new interval.Interval('P8'));
}
this.unison = intervalCache[0];
this.fifth = intervalCache[1];
this.octave = intervalCache[2];
this._v1n1 = undefined;
this._v1n2 = undefined;
this._v2n1 = undefined;
this._v2n2 = undefined;
this.v1n1 = v1n1;
this.v1n2 = v1n2;
this.v2n1 = v2n1;
this.v2n2 = v2n2;
this.vIntervals = [];
this.hIntervals = [];
this._key = undefined;
if (analyticKey !== undefined) {
this.key = analyticKey;
}
if (
v1n1 !== undefined
&& v1n2 !== undefined
&& v2n1 !== undefined
&& v2n2 !== undefined
) {
this._findIntervals();
}
}
_setVoiceNote(value, which) {
if (value === undefined) {
this[which] = value;
} else if (typeof value === 'string') {
this[which] = new note.Note(value);
} else if (value.classes.includes('Note')) {
this[which] = value;
} else {
const n = new note.Note(value.nameWithOctave);
n.duration.quarterLength = 0.0;
this[which] = n;
}
}
get v1n1() {
return this._v1n1;
}
set v1n1(value) {
this._setVoiceNote(value, '_v1n1');
}
get v1n2() {
return this._v1n2;
}
set v1n2(value) {
this._setVoiceNote(value, '_v1n2');
}
get v2n1() {
return this._v2n1;
}
set v2n1(value) {
this._setVoiceNote(value, '_v2n1');
}
get v2n2() {
return this._v2n2;
}
set v2n2(value) {
this._setVoiceNote(value, '_v2n2');
}
get key() {
return this._key;
}
set key(keyValue) {
if (typeof keyValue === 'string') {
keyValue = new key.Key(
key.convertKeyStringToMusic21KeyString(keyValue)
);
}
this._key = keyValue;
}
_findIntervals() {
this.vIntervals.push(new interval.Interval(this.v1n1, this.v2n1));
this.vIntervals.push(new interval.Interval(this.v1n2, this.v2n2));
this.hIntervals.push(new interval.Interval(this.v1n1, this.v1n2));
this.hIntervals.push(new interval.Interval(this.v2n1, this.v2n2));
}
motionType() {
if (this.obliqueMotion()) {
return MotionType.oblique;
} else if (this.parallelMotion()) {
return MotionType.parallel;
} else if (this.similarMotion()) {
return MotionType.similar;
} else if (this.contraryMotion()) {
return MotionType.contrary;
} else if (this.antiParallelMotion()) {
return MotionType.antiParallel;
} else if (this.noMotion()) {
return MotionType.noMotion;
}
return undefined;
}
noMotion() {
for (const iV of this.hIntervals) {
if (iV.name !== 'P1') {
return false;
}
}
return true;
}
obliqueMotion() {
if (this.noMotion()) {
return false;
}
for (const iH of this.hIntervals) {
if (iH.name === 'P1') {
return true;
}
}
return false;
}
similarMotion() {
if (this.noMotion()) {
return false;
}
if (this.hIntervals[0].direction === this.hIntervals[1].direction) {
return true;
} else {
return false;
}
}
parallelMotion(requiredInterval) {
if (!this.similarMotion()) {
return false;
}
if (
this.vIntervals[0].directedSimpleName
!== this.vIntervals[1].directedSimpleName
) {
return false;
}
if (requiredInterval === undefined) {
return true;
}
if (typeof requiredInterval === 'string') {
requiredInterval = new interval.Interval(requiredInterval);
}
if (this.vIntervals[0].simpleName === requiredInterval.simpleName) {
return true;
} else {
return false;
}
}
contraryMotion() {
if (this.noMotion()) {
return false;
}
if (this.obliqueMotion()) {
return false;
}
if (this.hIntervals[0].direction === this.hIntervals[1].direction) {
return false;
} else {
return true;
}
}
outwardContraryMotion() {
return (
this.contraryMotion()
&& this.hIntervals[0].direction === interval.Direction.ASCENDING
);
}
inwardContraryMotion() {
return (
this.contraryMotion()
&& this.hIntervals[0].direction === interval.Direction.DESCENDING
);
}
antiParallelMotion(simpleName) {
if (!this.contraryMotion()) {
return false;
}
if (this.vIntervals[0].simpleName !== this.vIntervals[1].simpleName) {
return false;
}
if (simpleName === undefined) {
return true;
}
if (typeof simpleName === 'string') {
if (this.vIntervals[0].simpleName === simpleName) {
return true;
} else {
return false;
}
} else if (this.vIntervals[0].simpleName === simpleName.simpleName) {
return true;
} else {
return false;
}
}
parallelInterval(thisInterval) {
if (!(this.parallelMotion() || this.antiParallelMotion())) {
return false;
}
if (typeof thisInterval === 'string') {
thisInterval = new interval.Interval(thisInterval);
}
if (this.vIntervals[0].semiSimpleName === thisInterval.semiSimpleName) {
return true;
} else {
return false;
}
}
parallelFifth() {
return this.parallelInterval(this.fifth);
}
parallelOctave() {
return this.parallelInterval(this.octave);
}
parallelUnison() {
return this.parallelInterval(this.unison);
}
parallelUnisonOrOctave() {
return this.parallelUnison() || this.parallelOctave();
}
hiddenInterval(thisInterval) {
if (this.parallelMotion()) {
return false;
}
if (!this.similarMotion()) {
return false;
}
if (typeof thisInterval === 'string') {
thisInterval = new interval.Interval(thisInterval);
}
if (this.vIntervals[1].simpleName === thisInterval.simpleName) {
return true;
} else {
return false;
}
}
hiddenFifth() {
return this.hiddenInterval(this.fifth);
}
hiddenOctave() {
return this.hiddenInterval(this.octave);
}
// True if either note in voice 1 is lower than the corresponding voice 2 note
voiceCrossing() {
return (
this.v1n1.pitch.ps < this.v2n1.pitch.ps
|| this.v1n2.pitch.ps < this.v2n2.pitch.ps
);
}
voiceOverlap() {
return (
this.v1n2.pitch.ps < this.v2n1.pitch.ps
|| this.v2n2.pitch.ps > this.v1n1.pitch.ps
);
}
/**
* isProperResolution - Checks whether the voice-leading quartet resolves correctly according to standard
* counterpoint rules. If the first harmony is dissonant (d5, A4, or m7) it checks
* that these are correctly resolved. If the first harmony is consonant, True is returned.
*
* The key parameter should be specified to check for motion in the bass from specific
* note degrees. If it is not set, then no checking for scale degrees takes place.
*
* Diminished Fifth: in by contrary motion to a third, with 7 resolving up to 1 in the bass
* Augmented Fourth: out by contrary motion to a sixth, with chordal seventh resolving
* down to a third in the bass.
* Minor Seventh: Resolves to a third with a leap form 5 to 1 in the bass
*
* @return {boolean} true if proper or rules do not apply; false if improper
*/
isProperResolution() {
if (this.noMotion()) {
return true;
}
let scale;
let n1degree;
let n2degree;
if (this.key !== undefined) {
scale = this.key.getScale();
n1degree = scale.getScaleDegreeFromPitch(this.v2n1);
n2degree = scale.getScaleDegreeFromPitch(this.v2n2);
}
// catches case of #7 in minor
if (
this.key !== undefined
&& this.key.mode === 'minor'
&& (n1degree === undefined || n2degree === undefined)
) {
const scale2 = this.key.getScale('melodic-minor'); // gets ascending form
if (n1degree === undefined) {
n1degree = scale2.getScaleDegreeFromPitch(this.v2n1);
}
if (n2degree === undefined) {
n2degree = scale2.getScaleDegreeFromPitch(this.v2n2);
}
}
const firstHarmony = this.vIntervals[0].simpleName;
const secondHarmony = this.vIntervals[1].generic.simpleUndirected;
if (firstHarmony === 'P4') {
if (this.v1n1.pitch.ps >= this.v1n2.pitch.ps) {
return true;
} else {
return false;
}
} else if (firstHarmony === 'd5') {
if (scale !== undefined && n1degree !== 7) {
return true;
}
if (scale !== undefined && n2degree !== 1) {
return false;
}
return this.inwardContraryMotion() && secondHarmony === 3;
} else if (firstHarmony === 'A4') {
if (scale !== undefined && n1degree !== 4) {
return true;
}
if (scale !== undefined && n2degree !== 3) {
return false;
}
return this.outwardContraryMotion() && secondHarmony === 6;
} else if (firstHarmony === 'm7') {
if (scale !== undefined && n1degree !== 5) {
return true;
}
if (scale !== undefined && n2degree !== 1) {
return false;
}
return secondHarmony === 3;
} else {
return true;
}
}
}