midi

Type Aliases

NoteKey

type NoteKey = typeof noteKeys[number];

Defined in: midi.ts:22

---

ScaleName

type ScaleName = keyof typeof scaleIntervals;

Defined in: midi.ts:131

---

WhiteKey

type WhiteKey = typeof whiteKeys[number];

Defined in: midi.ts:5

Variables

noteKeys

const noteKeys: readonly ["C", "C#", "D", "D#", "E", "F", "F#", "G", "G#", "A", "A#", "B"];

Defined in: midi.ts:7

---

scaleIntervals

const scaleIntervals: object;

Defined in: midi.ts:109

Semitones above the root, for each supported scale.

Every entry starts at 0 and stays inside one octave, so a scale is a set of pitch classes rather than a set of notes: inScale compares against it with the octave taken out.

ionian and aeolian are the same sets as major and naturalMinor; both spellings are here because both are what someone reaches for depending on whether they are thinking in keys or in modes.

Type Declaration

aeolian

readonly aeolian: readonly [0, 2, 3, 5, 7, 8, 10];

blues

readonly blues: readonly [0, 3, 5, 6, 7, 10];

chromatic

readonly chromatic: readonly [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11];

dorian

readonly dorian: readonly [0, 2, 3, 5, 7, 9, 10];

harmonicMinor

readonly harmonicMinor: readonly [0, 2, 3, 5, 7, 8, 11];

ionian

readonly ionian: readonly [0, 2, 4, 5, 7, 9, 11];

locrian

readonly locrian: readonly [0, 1, 3, 5, 6, 8, 10];

lydian

readonly lydian: readonly [0, 2, 4, 6, 7, 9, 11];

major

readonly major: readonly [0, 2, 4, 5, 7, 9, 11];

majorPentatonic

readonly majorPentatonic: readonly [0, 2, 4, 7, 9];

melodicMinor

readonly melodicMinor: readonly [0, 2, 3, 5, 7, 9, 11];

minorPentatonic

readonly minorPentatonic: readonly [0, 3, 5, 7, 10];

mixolydian

readonly mixolydian: readonly [0, 2, 4, 5, 7, 9, 10];

naturalMinor

readonly naturalMinor: readonly [0, 2, 3, 5, 7, 8, 10];

phrygian

readonly phrygian: readonly [0, 1, 3, 5, 7, 8, 10];

wholeTone

readonly wholeTone: readonly [0, 2, 4, 6, 8, 10];

---

whiteKeys

const whiteKeys: readonly ["A", "B", "C", "D", "E", "F", "G"];

Defined in: midi.ts:3

Functions

inScale()

function inScale(
   note, 
   root, 
   name
): boolean;

Defined in: midi.ts:144

Whether a note belongs to a scale, regardless of the octave either sits in.

Parameters

Parameter	Type	Description
note	string | number	noteNumber: 0 ~ 127 or noteName e.g. 'C3'
root	string | number	the note the scale is built on, in the same two forms
name	| "major" | "naturalMinor" | "harmonicMinor" | "melodicMinor" | "ionian" | "dorian" | "phrygian" | "lydian" | "mixolydian" | "aeolian" | "locrian" | "majorPentatonic" | "minorPentatonic" | "blues" | "wholeTone" | "chromatic"	-

Returns

boolean

Example

inScale('F#4', 'D3', 'major') // true

---

isBlackKey()

function isBlackKey(note): boolean;

Defined in: midi.ts:83

Parameters

Parameter	Type	Description
note	string | number	noteNumber: 0 ~ 127 or noteName e.g. 'C3'

Returns

boolean

---

isWhiteKey()

function isWhiteKey(note): boolean;

Defined in: midi.ts:67

Parameters

Parameter	Type	Description
note	string | number	noteNumber: 0 ~ 127 or noteName e.g. 'C3'

Returns

boolean

---

noteKey()

function noteKey(noteNumber): "A" | "B" | "C" | "D" | "E" | "F" | "G" | "C#" | "D#" | "F#" | "G#" | "A#";

Defined in: midi.ts:60

Convert noteNumber to noteKey

Parameters

Parameter	Type
noteNumber	number

Returns

"A" | "B" | "C" | "D" | "E" | "F" | "G" | "C#" | "D#" | "F#" | "G#" | "A#"

---

noteName()

function noteName(noteNumber): 
  | `A${number}`
  | `B${number}`
  | `C${number}`
  | `D${number}`
  | `E${number}`
  | `F${number}`
  | `G${number}`
  | `C#${number}`
  | `D#${number}`
  | `F#${number}`
  | `G#${number}`
  | `A#${number}`;

Defined in: midi.ts:51

Convert noteNumber to noteName C-1 = 0 G9 = 127

Parameters

Parameter	Type	Description
noteNumber	number	noteNumber

Returns

| `A${number}` | `B${number}` | `C${number}` | `D${number}` | `E${number}` | `F${number}` | `G${number}` | `C#${number}` | `D#${number}` | `F#${number}` | `G#${number}` | `A#${number}`

---

noteNumber()

function noteNumber(noteName): number;

Defined in: midi.ts:38

Convert noteName to noteNumber

Parameters

Parameter	Type
noteName	string

Returns

number

---

noteToFrequency()

function noteToFrequency(
   note, 
   detune?, 
   a4?
): number;

Defined in: midi.ts:93

Parameters

Parameter	Type	Default value	Description
note	string | number	undefined	noteNumber: 0 ~ 127 or noteName e.g. 'C3'
detune	number	0	[cent]
a4	number	440	A4 frequency [Hz]

Returns

number

frequency [Hz]

---

parseNoteName()

function parseNoteName(noteName): object;

Defined in: midi.ts:24

Parameters

Parameter	Type
noteName	string

Returns

object

accidental

accidental: "" | "b" | "#" | "##" | "bb";

letter

letter: "A" | "B" | "C" | "D" | "E" | "F" | "G";

octave

octave: number;

---

scaleNotes()

function scaleNotes(
   root, 
   name, 
   octaves?
): number[];

Defined in: midi.ts:168

The notes of a scale, ascending from root.

The octave above the root is not included: ask for more octaves instead, so that concatenating the result of two calls does not repeat a note.

Parameters

Parameter	Type	Default value	Description
root	string | number	undefined	noteNumber: 0 ~ 127 or noteName e.g. 'C3'
name	| "major" | "naturalMinor" | "harmonicMinor" | "melodicMinor" | "ionian" | "dorian" | "phrygian" | "lydian" | "mixolydian" | "aeolian" | "locrian" | "majorPentatonic" | "minorPentatonic" | "blues" | "wholeTone" | "chromatic"	undefined	-
octaves	number	1	how many octaves to cover

Returns

number[]

Example

scaleNotes('C3', 'majorPentatonic') // [48, 50, 52, 55, 57]