Cross Application Audio Analysis With The Web Audio Api

I am writing an audio visualizer application using the web audio api and the three.js library. I've had a lot of success using the html5 element to get audio from a local mp3 or a

Solution 1:

There's no "built-in" way to do this. (On purpose, actually, because it raises a lot of security and privacy concerns.) It's possible to set up a loopback audio driver on a client's machine, and use that as the audio output device for Spotify or iTunes, and capture its input in Web Audio; that's not a great end-user solution, though, of course.