Music written in Javascript

This project demonstrates writing music in Javascript. In the beginning I used NodeJS with MIDI to control a synth, and then got into 4klang which is a very compact but extremely powerful synth, which finally inspired me to atttempt writing a synth in WebAssembly running entirely in the browser.

Webassembly music in the browser

This is a live-coding environment for music running entirely in the browser, synthesizing music in webassembly using AssemblyScript.

You can test it yourself at the hosted app: https://webassemblymusic.pages.dev/

The two repos used for the IFC 2026 talk load directly via the ?gitrepo= parameter:

• https://webassemblymusic.pages.dev/?gitrepo=ifc2026-concert.gitfactory.testnet
• https://webassemblymusic.pages.dev/?gitrepo=ifc2026-faust2as.gitfactory.testnet

An older version is hosted at petersalomonsen.com (load a gist with the gist url parameter, or remove it for a clean project): https://petersalomonsen.com/webassemblymusic/livecodev2/?gist=5b795090ead4f192e7f5ee5dcdd17392

Demo videos: https://www.youtube.com/watch?v=C8j_ieOm4vE&list=PLv5wm4YuO4IxRDu1k8fSBVuUlULA8CRa7

Sources are in the wasmaudioworklet folder. See the documentation guides for writing songs, animating visuals, and hosting projects.

There are also more resources like articles and earlier versions at https://petersalomonsen.com

4klang

My experiments with the 4klang synth can be found int the 4klang folder.

If you just want to listen to the songs: https://soundcloud.com/psalomo/4klang-lazy-grooves https://soundcloud.com/psalomo/4klang-first-attempt

You may check out the windows exe of the "first attempt" song (link to zip with exe found in video description):

https://www.youtube.com/watch?v=zHrbLSjKmxQ

NodeJS MIDI

My first attempt on writing music with Javascript used NodeJS with MIDI routed to ZynAddSubFX for the sounds

https://youtu.be/oPfOeEbM4M0

And you can listen to the song songs/upbeat.js here: https://soundcloud.com/psalomo/80s-nostalgica

Run directly from nodejs, only dependes on the node midi package, and connect to a midi device.

License

This project is licensed under the GNU General Public License v3.0 — see LICENSE for the full text. Bundled third-party components (e.g. 4klang) retain their own licenses.