Q:

How to Access Website Audio Source with Javascript?

So, I would like to use the Web Audio API to manipulate audio that is streaming from websites.  (For example, create a dynamic bass boost for listening via Soundcloud.)  
I'm familiar with the Web Audio API and know how to use it to stream audio from the microphone or create a synthesizer. 
However, I cannot determine is the Web Audio API (or Javascript, in general) is capable of "grabbing" audio from an already existing audio source.  Is it possible to access audio from a site? 
Thanks.

A:

No, this is not something that the Web Audio API can do. Media elements must be available within the document to use them for a MediaElementAudioSourceNode.
(And it will probably never be possible on a cross-origin basis -- browser developers generally take a dim view of APIs that could potentially lead to information leaking across origins.)

