JSONloops is a real-time, multiuser audio sequencer for node.js and the browser.
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JSONLoops is a multi-user audio sequencer reminiscent of Fruityloops. Audio playback is handled by node.js servers, while multiple browsers act as control devices. Songs are stored in the JSONloop format, which are simply nested JSON arrays.


This is Alpha software which was created for NYC Music Hack Day 2011. We won best collaborative project. This library works and is awesome. It could be epic if we all work on it.

Video Demo



  npm install JSONloops

Now you will have to rebuild node as 32bit, since irrKlang doesn't support 64 arch's yet.

  cd /path/to/node
  ./configure --dest-cpu=ia32
  make install

We'll be replacing this last step with a much easier process soon.


To get started, you'll want to clone the JSONloops project and use the demo server

git clone https://github.com/Marak/JSONloops.git
cd jsonloops
[sudo] npm install .
node server.js

The audio sequencer will now start playing on your local machine, you'll hear sounds. To access a control interface for your JSONloops server, visit http://localhost:8080/

Why did you build this?

Because I'm insane.

The JSONLoop format

A JSONLoop is nothing but a nested JSON array that follows a somewhat specific format.

the arrays are nested in the following hierarchy 

*       BEATS

Check out the nyc.json file or metronome.json file for example loops.

can anyone create a proper json-schema to represent this? it also has to validate the loop is well formed...


Marak Squires - Created project, JavaScript, HTML, CSS, invented the JSONloops format, built core sequencing code

Elijah Insua - Writer of C bindings, solver of the hard problems

hij1nx - Writer of C bindings, JavaScript, HTML, CSS UX and UI.