tonal-note

note

tonal-note is a collection of functions to manipulate musical notes in scientific notation

This is part of tonal music theory library.

Usage

import * as note from 'tonal-note'
// or const note = require('tonal-note')
note.name('bb2') // => 'Bb2'
note.chroma('bb2') // => 10
note.midi('a4') // => 69
note.freq('a4') // => 440
note.oct('G3') // => 3

// part of tonal
const tonal = require('tonal')
tonal.note.midi('d4') // => 62

Install

API Documentation

• note
  • .isNote ⇒ boolean
  • .midiToFreq ⇒ Number
  • .freqToMidi ⇒ Number
  • .chroma ⇒ Integer
  • .stepToLetter ⇒ string
  • .altToAcc ⇒ String
  • .name() ⇒ string
  • .pc() ⇒ string
  • .midi(note) ⇒ Integer
  • .freq(note) ⇒ Number
  • .oct(note) ⇒ Integer
  • .step(note) ⇒ Integer
  • .alt(note) ⇒ Integer
  • .fromMidi(midi, [boolean]) ⇒ string

note.isNote ⇒ boolean

Test if the given string is a note

Kind: static constant of note

Param	Type
name	String

note.midiToFreq ⇒ Number

Get the frequency from midi number

Kind: static constant of note
Returns: Number - the frequency or null if not valid note midi

Param	Type	Description
midi	Number	the note midi number
tuning	Number	(Optional) 440 by default

note.freqToMidi ⇒ Number

Get the midi number from a frequency in hertz. The midi number can contain decimals (with two digits precission)

Kind: static constant of note

Param	Type
frequency	Number

Example

note.freqToMidi(220)); //=> 57;
note.freqToMidi(261.62)); //=> 60;
note.freqToMidi(261)); //=> 59.96;

note.chroma ⇒ Integer

Return the chroma of a note. The chroma is the numeric equivalent to the pitch class, where 0 is C, 1 is C# or Db, 2 is D... 11 is B

Kind: static constant of note
Returns: Integer - the chroma number

Param	Type	Description
note	string	the note name

Example

const note = require('tonal-note')
note.chroma('Cb') // => 11
['C', 'D', 'E', 'F'].map(note.chroma) // => [0, 2, 4, 5]

note.stepToLetter ⇒ string

Given a step number return it's letter (0 = C, 1 = D, 2 = E)

Kind: static constant of note
Returns: string - the letter

Param	Type
step	number

Example

note.stepToLetter(3) // => "F"

note.altToAcc ⇒ String

Given an alteration number, return the accidentals

Kind: static constant of note

Param	Type
alt	Number

Example

note.altToAcc(-3) // => 'bbb'

note.name() ⇒ string

Given a note name, return the note name or null if not valid note. The note name will ALWAYS have the letter in upercase and accidentals using # or b

Can be used to test if a string is a valid note name.

Kind: static method of note

Type
Pitch | string

Example

const note = require('tonal-note')
note.name('cb2') // => 'Cb2'
['c', 'db3', '2', 'g+', 'gx4'].map(note.name) // => ['C', 'Db3', null, null, 'G##4']

note.pc() ⇒ string

Get pitch class of a note. The note can be a string or a pitch array.

Kind: static method of note
Returns: string - the pitch class

Type
string | Pitch

Example

tonal.pc('Db3') // => 'Db'
tonal.map(tonal.pc, 'db3 bb6 fx2') // => [ 'Db', 'Bb', 'F##']

note.midi(note) ⇒ Integer

Get the note midi number (an alias of tonal-midi toMidi function)

Kind: static method of note
Returns: Integer - the midi number or null if not valid pitch
See: midi.toMidi

Param	Type	Description
note	string | Number	the note to get the midi number from

Example

note.midi('C4') // => 60
note.midi(60) // => 60

note.freq(note) ⇒ Number

Get the frequency of a note

Kind: static method of note
Returns: Number - the frequency

Param	Type	Description
note	string | Number	the note name or midi note number

Example

note.freq('A4') // => 440
note.freq(69) // => 440

note.oct(note) ⇒ Integer

Get the octave of the given pitch

Kind: static method of note
Returns: Integer - the octave or null if doesn't have an octave or not a valid note

Param	Type	Description
note	string	the note

Example

note.oct('C#4') // => 4
note.oct('C') // => null
note.oct('blah') // => undefined

note.step(note) ⇒ Integer

Get the note step: a number equivalent of the note letter. 0 means C and 6 means B. This is different from chroma (see example)

Kind: static method of note
Returns: Integer - a number between 0 and 6 or null if not a note

Param	Type	Description
note	string	the note

Example

note.step('C') // => 0
note.step('Cb') // => 0
// usually what you need is chroma
note.chroma('Cb') // => 6

note.alt(note) ⇒ Integer

Get the note alteration: a number equivalent to the accidentals. 0 means no accidentals, negative numbers are for flats, positive for sharps

Kind: static method of note
Returns: Integer - the alteration

Param	Type	Description
note	string | Pitch	the note

Example

note.alt('C') // => 0
note.alt('C#') // => 1
note.alt('Cb') // => -1

note.fromMidi(midi, [boolean]) ⇒ string

Given a midi number, returns a note name. The altered notes will have flats unless explicitly set with the optional useSharps parameter.

Kind: static method of note
Returns: string - the note name

Param	Type	Description
midi	number	the midi note number
[boolean]		useSharps - (Optional) set to true to use sharps instead of flats

Example

const note = require('tonal-note')
note.fromMidi(61) // => 'Db4'
note.fromMidi(61, true) // => 'C#4'
// it rounds to nearest note
note.fromMidi(61.7) // => 'D4'