tonal-notation

tonal-notation is a collection of functions to create and manipulate strings with music information.

This is part of tonal music theory library.

You can install via npm: npm i --save tonal-notation

API Reference

toStep(letter) ⇒ Integer

Given a letter, return step

Returns: Integer - the step number (from 0 to 6)

| Param | Type | Description | | --- | --- | --- | | letter | String | the letter |

isStep(step) ⇒ Boolean

Test if a number is a valid step number (a number from 0 to 6)

Returns: Boolean - true if it's a valid step number, false otherwise

| Param | Type | Description | | --- | --- | --- | | step | Integer | the step number |

toLetter(step) ⇒ String

Given a step, return a letter

Returns: String - the note letter or null if not valid step number

| Param | Type | Description | | --- | --- | --- | | step | Integer | the step number |

areFlats(str) ⇒ Boolean

Test if a string are all flats (b) chars

Returns: Boolean - true if all charaters are b, false otherwise

| Param | Type | Description | | --- | --- | --- | | str | String | the string to test |

areSharps(str) ⇒ Boolean

Test if a string are all sharps (#) chars

Returns: Boolean - true if all charaters are #, false otherwise

| Param | Type | Description | | --- | --- | --- | | str | String | the string to test |

toAlt(accidentals) ⇒ Integer

Given an accidentals string return its alteration, the number of semitones (positive for sharps, negative for flats, 0 for none)

Returns: Integer - the alteration number of null if not a valid accidental strings

| Param | Type | Description | | --- | --- | --- | | accidentals | String | the string to parse |

Example

toAlt('###') // => 3
toAlt('bbb') // => -3

toAcc(alteration) ⇒ String

Given an alteration number, returns the accidentals string

Returns: String - the accidental string

| Param | Type | Description | | --- | --- | --- | | alteration | Integer | the number of semitones (positive and negative values are accepted for sharps and flats) |

Example

toAcc(3) // => '###'
toAcc(-3) // => 'bbb'