Nice, I could reuse some of the sources one day, my "perpetual pet project " is a web audio player, with the same idea of unifying sources into the same interface.

Here's a screenshot of current version: https://dl.dropboxusercontent.com/u/177896/Capture-webplayer...

It's 100% client side (compiles to a html/js single page app), I have a separate optional server + client plugin to handle my local files.