tonal is a music theory library. Contains functions to manipulate tonal
elements of music (note, intervals, chords, scales, modes, keys). It deals with
abstractions (not actual music or sound).
tonal is implemented in Typescript and published as a collection of Javascript
npm packages.
It uses a functional programing style: all functions are pure, there is no data mutation, and entities are represented by data structures instead of objects.
import { Interval, Note, Scale } from "@tonaljs/tonal";
Note.midi("A4"); // => 60
Note.freq("a4").freq; // => 440
Note.accidentals("c#2"); // => '#'
Note.transpose("C4", "5P"); // => "G4"
Interval.semitones("5P"); // => 7
Interval.distance("C4", "G4"); // => "5P"
Scale.get("C major").notes; // =>["C", "D", "E", "F", "G", "A", "B"];
Install all packages at once:
npm install --save @tonaljs/tonal
Tonal is compatible with both ES5 and ES6 modules, and browser.
import:import { Note, Scale } from "@tonaljs/tonal";
require:const { Note, Scale } = require("@tonaljs/tonal");
You can use the browser version from jsdelivr CDN directly in your html:
<script src="https://cdn.jsdelivr.net/npm/@tonaljs/tonal/browser/tonal.min.js"></script>
<script>
console.log(Tonal.Key.minorKey("Ab"));
</script>
Or if you prefer, grab the minified browser ready version from the repository.
@tonaljs/tonal includes all published modules.
Although the final bundle it is small (~10kb minified and gzipped), you can reduce bundle sizes even more by installing the modules individually, and importing only the functions you need:
npm i @tonaljs/note
import { transpose } from "@tonaljs/note";
transpose("A4", "P5");
Generally, you just need to install:
The API documentation lives inside README.md file of each module
Read contributing document for instructions
This library takes inspiration from other music theory libraries:
Showcase of projects that are using Tonal:
Thank you all!
Add your project here by editing this file
$ claude mcp add tonal \
-- python -m otcore.mcp_server <graph>