tonal-freq

freq

tonal-freq is a collection of functions to perform calculations related to frequencies.

This is part of tonal music theory library.

Usage

var freq = require('tonal-freq')
freq.toFreq('A4') // => 440
freq.note(440) // => 'A4'
freq.noteAndDetune(320) // => ['C4', 200]

Install

API Documentation

• freq
  • .eqTempFreq(ref, maxDecimals, note) ⇒ Number
  • .toFreq(note) ⇒ Float
  • .eqTempFreqToMidi(tuning, freq) ⇒ Number
  • .toMidi(freq) ⇒ Number
  • .note(freq, useSharps) ⇒ String
  • .cents(base, freq) ⇒ Integer

freq.eqTempFreq(ref, maxDecimals, note) ⇒ Number

Return the equal tempered frequency of a note.

This function can be partially applied if note parameter is not present.

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

Param	Type	Description
ref	Float	the tuning reference
maxDecimals	Integer	(Optional) the maximum number of decimals (all by default)
note	String | Pitch	the note to get the frequency from

Example

eqTempFreq(444, 4, 'C3')
const toFreq = eqTempFreq(444, 2)
toFreq('A3') // => 222

freq.toFreq(note) ⇒ Float

Get the frequency of note with 2 decimals precission using A4 440Hz tuning

This is an alias for: eqTempFreq(440, 2, <note>)

Kind: static method of freq
Returns: Float - the frequency in herzs

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

Example

freq.toFreq('A4') // => 440
freq.toFreq('C4') // => 261.63

freq.eqTempFreqToMidi(tuning, freq) ⇒ Number

Get the midi note from a frequency in equal temperament scale. You can specify the number of decimals of the midi number.

Kind: static method of freq
Returns: Number - the midi number

Param	Type	Description
tuning	Float	(Optional) the reference A4 tuning (440Hz by default)
freq	Number	the frequency

freq.toMidi(freq) ⇒ Number

Get midi number from frequency with two decimals of precission.

This is an alisas for: eqTempFreqToMidi(440, 2, <freq>)

Kind: static method of freq
Returns: Number - midi number

Param	Type
freq	Float

Example

freq.toMidi(361) // => 59.96

freq.note(freq, useSharps) ⇒ String

Get note name from frequency using an equal temperament scale with 440Hz as reference

Kind: static method of freq
Returns: String - note name

Param	Type	Description
freq	Float
useSharps	Boolean	(Optional) set to true to use sharps instead of flats

Example

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

freq.cents(base, freq) ⇒ Integer

Get difference in cents between two frequencies. The frequencies can be expressed with hertzs or midi numbers or note names

Kind: static method of freq
Returns: Integer - The difference in cents

Param	Type
base	Float | Integer | String
freq	Float | Integer | String

Example

import { cents } from 'tonal-freq'
cents('C4', 261) // => -4