79 lines
2.6 KiB
TypeScript
79 lines
2.6 KiB
TypeScript
const SCALES: Record<string, number[]> = {
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major: [0, 2, 4, 5, 7, 9, 11],
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naturalMinor: [0, 2, 3, 5, 7, 8, 10],
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harmonicMinor: [0, 2, 3, 5, 7, 8, 11],
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melodicMinor: [0, 2, 3, 5, 7, 9, 11],
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dorian: [0, 2, 3, 5, 7, 9, 10],
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phrygian: [0, 1, 3, 5, 7, 8, 10],
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lydian: [0, 2, 4, 6, 7, 9, 11],
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mixolydian: [0, 2, 4, 5, 7, 9, 10],
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aeolian: [0, 2, 3, 5, 7, 8, 10],
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locrian: [0, 1, 3, 5, 6, 8, 10],
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wholeTone: [0, 2, 4, 6, 8, 10],
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majorPentatonic: [0, 2, 4, 7, 9],
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minorPentatonic: [0, 3, 5, 7, 10],
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chromatic: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11],
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blues: [0, 3, 5, 6, 7, 10],
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diminished: [0, 2, 3, 5, 6, 8, 9, 11],
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neapolitanMinor: [0, 1, 3, 5, 7, 8, 11],
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neapolitanMajor: [0, 1, 3, 5, 7, 9, 11],
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enigmatic: [0, 1, 4, 6, 8, 10, 11],
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doubleHarmonic: [0, 1, 4, 5, 7, 8, 11],
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octatonic: [0, 2, 3, 5, 6, 8, 9, 11],
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bebopDominant: [0, 2, 4, 5, 7, 9, 10, 11],
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bebopMajor: [0, 2, 4, 5, 7, 8, 9, 11],
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bebopMinor: [0, 2, 3, 5, 7, 8, 9, 11],
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bebopDorian: [0, 2, 3, 4, 5, 7, 9, 10],
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harmonicMajor: [0, 2, 4, 5, 7, 8, 11],
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hungarianMinor: [0, 2, 3, 6, 7, 8, 11],
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hungarianMajor: [0, 3, 4, 6, 7, 9, 10],
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oriental: [0, 1, 4, 5, 6, 9, 10],
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romanianMinor: [0, 2, 3, 6, 7, 9, 10],
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spanishGypsy: [0, 1, 4, 5, 7, 8, 10],
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jewish: [0, 1, 4, 5, 7, 8, 10],
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hindu: [0, 2, 4, 5, 7, 8, 10],
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japanese: [0, 1, 5, 7, 8],
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hirajoshi: [0, 2, 3, 7, 8],
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kumoi: [0, 2, 3, 7, 9],
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inSen: [0, 1, 5, 7, 10],
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iwato: [0, 1, 5, 6, 10],
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yo: [0, 2, 5, 7, 9],
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minorBlues: [0, 3, 5, 6, 7, 10],
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algerian: [0, 2, 3, 5, 6, 7, 8, 11],
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augmented: [0, 3, 4, 7, 8, 11],
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balinese: [0, 1, 3, 7, 8],
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byzantine: [0, 1, 4, 5, 7, 8, 11],
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chinese: [0, 4, 6, 7, 11],
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egyptian: [0, 2, 5, 7, 10],
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eightToneSpanish: [0, 1, 3, 4, 5, 6, 8, 10],
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hawaiian: [0, 2, 3, 5, 7, 9, 10],
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hindustan: [0, 2, 4, 5, 7, 8, 10],
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persian: [0, 1, 4, 5, 6, 8, 11],
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eastIndianPurvi: [0, 1, 4, 6, 7, 8, 11],
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orientalA: [0, 1, 4, 5, 6, 9, 10],
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};
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export function scale(
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n: number,
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scaleName: string = "major",
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octave: number = 4
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): number {
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/**
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* Returns the MIDI note number for the given scale degree in the given scale.
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* @param {number} n - The scale degree, where 0 is the tonic.
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* @param {string} scaleName - The name of the scale.
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* @param {number} octave - The octave number.
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* @returns {number} The MIDI note number.
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*/
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const scale = SCALES[scaleName];
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if (!scale) {
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throw new Error(`Unknown scale ${scaleName}`);
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}
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let index = n % scale.length;
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if (index < 0) index += scale.length; // adjust for negative indexes
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let additionalOctaves = Math.floor(n / scale.length);
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return 60 + (octave + additionalOctaves) * 12 + scale[index];
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}
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