https://github.com/danigb/pitch-transpose

Simple and fast pitch transposition
https://github.com/danigb/pitch-transpose

Last synced: 7 months ago
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Simple and fast pitch transposition

• Host: GitHub
• URL: https://github.com/danigb/pitch-transpose
• Owner: danigb
• License: mit
• Created: 2015-10-14T09:10:26.000Z (over 10 years ago)
• Default Branch: master
• Last Pushed: 2015-10-21T19:35:39.000Z (over 10 years ago)
• Last Synced: 2024-12-27T11:34:49.036Z (over 1 year ago)
• Language: JavaScript
• Size: 129 KB
• Stars: 2
• Watchers: 4
• Forks: 1
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGELOG
  • License: LICENSE

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README

          
# pitch-transpose

[![Build Status](https://travis-ci.org/danigb/pitch-transpose.svg?branch=master)](https://travis-ci.org/danigb/pitch-transpose)

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[![js-standard-style](https://img.shields.io/badge/code%20style-standard-brightgreen.svg?style=flat)](https://github.com/feross/standard)

[![npm](https://img.shields.io/npm/v/pitch-transpose.svg)](https://www.npmjs.com/package/pitch-transpose)

[![array-notation](https://img.shields.io/badge/array--notation-compatible-yellow.svg)](https://github.com/danigb/pitch-array)

Simple and fast pitch transposition:

```js

transpose('E2', '2M') // => 'F#2'

transpose('F4', '3m') // => 'Ab4'

```

This is piece of a complete music manipulation library called [tonal](https://github.com/danigb/tonal)

## Installation

Install the npm module: `npm i --save pitch-transpose` and use it:

```js

var transpose = require('pitch-transpose')

transpose('3m', 'G') // => 'Bb'

```

For browser environments you need browserify, webpack or a similar tool (or use [tonal](https://github.com/danigb/tonal))

## Usage

#### Pitch transposition

The simplest usage is with a pitch and interval (the order doesn't matter):

```js

transpose('C2', '4A') // => 'F#2'

transpose('4A', 'C2') // => 'F#2'

```

#### Pitch class transposition

You can transpose pitch classes (pitches without octaves), and the returned value will be a pitch class:

```js

tranpose('A', '3M') // => 'C#'

tranpose('A5', '3M') // => 'C#5'

```

#### Transposers

Also, you can partially apply to get a transposer:

```js

var major3th = transpose('3M')

major3th('D') // => 'F#'

```

#### Work with pitch or interval arrays

Partially applied transposers allows to work with arrays seamlessly:

```

['C', 'D', 'E', 'F', 'G'].map(transpose('3M')) // => ['E', 'F#', 'G#', 'A', 'B']

['1P', '3m', '5P'].map(transpose('C')) // => ['C', 'Eb', 'G']

```

#### Using different interval or pitch representations

This library can work with [pitches or intervals expressed as arrays](https://github.com/danigb/a-pitch):

```js

transpose([0, 1, 3], [2, 0, 0]) // => [3, 1, 3]

// is the same as: transpose('C#3', '3M') => 'E#3'

```

It should be quite easy to write a custom parser/builder. TODO: write an example.

## API



















transpose(a, b) → {String|Array}









Transposes pitch by an interval



Parameters:


Name

Type

Description

a

String

|

Array

a pitch or interval in string or array notation


b

String

|

Array

a pitch or interval in string or array notation




Source:





index.js

, 

lineno 19







Returns:



the transposed pitch







Type





String

|

Array





Example

transpose('3m', 'C4') // => 'Eb4'

transpose('C4', '3m') // => 'Eb4'

tranpose([1, 0, 2], [3, -1, 0]) // => [3, 0, 2]







*generated with [docme](https://github.com/thlorenz/docme)*



## License

MIT License