chordy-svg

Node JS module for generating guitar chord diagrams in SVG format. Interval names are shown inside the dotted positions.

A <defs> element is written which contains the notes of the chord. This in turn can later be used by the user for audio previews etc.

<defs xmlns="http://www.w3.org/2000/svg" id="tonal">
  <style id="SvgjsStyle1101"/>
  <notes id="tonal-notes">C3:G3:B3:E4:G4</notes>
  <semitones id="tonal-semitones">8:15:19:24:27</semitones>
  <comment id="chord-comment"/>
</defs>

The GitHub page may contain more up to date code than the NPM release. Please check GitHub for the most recent updates.

It uses:

SVG.js for SVG manipulation.
svgdom to allow SVG.js to run server-side.
tonal music theory library for determining the notes and intervals of defined chords.

Demo

You can see this library being used at https://chords.gock.net/

Installation

Via NPM

Install module:

npm install chordy-svg --save

Via Git

Clone Git repository

git clone https://github.com/andygock/chordy-svg

Examples

Node Example

Create a node application test.js. This will create a SVG diagram and write the contents to stdout.

const ChordySvg = require('chordy-svg');

const voicing = {
    name: "Cmaj7",
    shape: "x35453",
    root: 2,
    comment: ""
};

const svg = new ChordySvg(voicing);
const data = svg.svg();
process.stdout.write(data);

If you've cloned the library from GitHub instead of using NPM, you'll need to replace require('chordy-svg') with the correct path, e.g require('./chordy-svg')

Create SVG and write to new file output.svg

node test.js > output.svg

Browser Example

chordy-svg.min.js is found in dist/ and can be built with npm build. Read the tests section further below with prewritten examples you can use.

    <div id="image"></div>

    <!-- use https://rawgit.com/danigb/tonal/master/dist/tonal.min.js for latest build -->
    <script src="https://cdn.rawgit.com/danigb/tonal/a105f292/dist/tonal.min.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/svg.js/2.6.3/svg.min.js"></script>
    <script src="chordy-svg.min.js"></script>
    <script type="text/javascript">
        // create new svg diagram
        var element = document.getElementById('image');
        var svg = new ChordySvg({ name: "Cmaj7", shape: "x35453", root: 2, comment: "Test comment" }, { target: element });
    </script>

Input

In the example above, we used:

const voicing = {
    name: "Cmaj7",
    shape: "x35453",
    root: 2,
    comment: ""
};

The properties for this object are:

name is the name of the chord and will be displayed as a title in the SVG
shape is the shape of the chord, starting from the lowest / thickest string.
- x: muted or skipped string.
- 0: open string (open strings not properly tested yet)
- [0-9a-f]: hexadecimal value refers to fret position. e.g b refers to fret position 11. Only up to fret position 15 (hex f) is permitted.
root is the root string. 0 refers to the lowest frequency / thickest string. On 6 string guitars with EADGBE tuning, 5 refers to the high E string. In the generated diagram, the dot for this position will be coloured red by default.

A second parameter to the ChordySvg() constructor may be used to set more custom parameters (documentation not complete yet).

Testing

NodeJS

Standalone testing (requires Mocha, you may need to run npm install mocha -g first)

git clone https://github.com/andygock/chordy-svg
cd chordy-svg
npm update
npm test

This will also generate some SVG files which you should check. Remove these files once you've finished with them.

rm -f *.svg

To publish npm package

npm run build
npm version (patch|minor|major)
npm publish
git push

Browser

Build browser targeted files dist/svg-chordy.js and dist/svg-chordy.min.js with:

npm run build

View file test/test.html

Notes

Not fully tested for chords with open strings.

jecker7/chordy-svg