– mashup soundcloud audio tracks is an experiment on collaborative realtime audio editing and music creation.
I did the project within the frame of  my BA thesis in audio production last year.

As I moved the code to github this week, I wanted to give a quick overview of the project and its technical underlyings, just in case someone might be interested :)

As the title of this post might already suggest, its about selecting and layering loops from audiofiles hosted on and thereby creating new music.

Bildschirmfoto 2013-01-24 um 20.46.08

Those collections of layered loops are called a session. Sessions can be created anonymously by everyone and are auto-saved on every action. By distributing the URL of a session other users can join and every action is synced between all users in realtime.
(complete mayhem, indeed :)

The application is built with HTML5 and JS w/ jQuery using the soundcloud API on the client side and runs on node.js & mongoDB with express, and mongoose on the server side.

I basically started the project to find out if you could play multiple loops asynchronous and synced with low latency using the Web Audio API while collaboratively working together with multiple users in realtime. 

As that turned out to be not only possible but performed real nicely, the experiment then developed in somewhat of an application and finally got a name and a face.

There’s a whole lot of things i’d like to implement / refactor and do when i get some time on my hands, as

– adding a “record” feature to record, save and export created sessions as audiofiles

– rewriting the client side with backbone.js (as things got a bit messy …)

– adding some audio effects to the tracks

– write some tests

I’d appreciate any form of contribution as much as any questions or feedback on the project :)

Feel free to check out the live version at or the sources at