MusicalScale TypeScript Library

Overview

This TypeScript library provides classes for representing musical scales and translating musical note names between English, German, and Japanese.

Usage

import { MusicalScale } from 'musical-scale';

// Create a new musical scale instance
const scale = MusicalScale.create();

// Set the scale to A major
scale.la().octave(4);

// Get the frequency of the current note
const frequency = scale.toFrequency();
console.log(`Frequency: ${frequency} Hz`);

// Convert the current note to MIDI note number
const midiNote = scale.toMIDINoteNumber();
console.log(`MIDI Note Number: ${midiNote}`);

// Get the note name in German and Japanese
const germanNote = scale.getNoteName().toGerman();
const japaneseNote = scale.getNoteName().toJapanese();

console.log(`German Note Name: ${germanNote}`);
console.log(`Japanese Note Name: ${japaneseNote}`);

API Document

MusicalScale Class

Represents a musical scale, allowing manipulation of notes and octaves.

This class is always the note name and octave are initialized. After this, when the pitch and octave to be explained, the sound of A4 is returned.

static create(): MusicalScale

Creates a new instance of MusicalScale.

do(): this

Sets the current note to C. Returns the MusicalScale instance for method chaining.

re(): this

Sets the current note to D. Returns the MusicalScale instance for method chaining.

mi(): this

Sets the current note to E. Returns the MusicalScale instance for method chaining.

fa(): this

Sets the current note to F. Returns the MusicalScale instance for method chaining.

so(): this

Sets the current note to G. Returns the MusicalScale instance for method chaining.

la(): this

Sets the current note to A. Returns the MusicalScale instance for method chaining.

ti(): this

Sets the current note to B. Returns the MusicalScale instance for method chaining.

octave(n: number): this

Sets the current octave to the specified value n. Returns the MusicalScale instance for method chaining.

sharp(): this

Raises the current note by a half step. Returns the MusicalScale instance for method chaining.

flat(): this

Lowers the current note by a half step. Returns the MusicalScale instance for method chaining.

toFrequency(roundFunc?: (x: number) => number): number

Calculates the frequency of the current note in Hertz. Optionally, roundFunc can be provided to round the frequency. Returns the calculated frequency.

toMIDINoteNumber(strict?: boolean): number

Converts the current note to its corresponding MIDI note number. If strict is true, it throws an error for out-of-range MIDI note numbers. Returns the MIDI note number.

getNoteName(): NoteNameTranslator

Returns a NoteNameTranslator instance representing the current note name and octave.

NoteNameTranslator Class

Translates musical note names between English, German, and Japanese.

constructor(noteName: NoteName, octave: number)

Constructs a new instance of NoteNameTranslator with an initial note name and octave.

toGerman(withOctave?: boolean): string

Returns the German translation of the note name, optionally including the octave.

toJapanese(withOctave?: boolean): string

Returns the Japanese translation of the note name, optionally including the octave.

toString(): string

Returns the original note name including the octave.