Excellent.<p>I've hosted hughrawlinson's demo code at <a href="http://diydsp.com/fun/meyda/" rel="nofollow">http://diydsp.com/fun/meyda/</a><p>And I've written a short blogpost teaching people what-the-heck feature extraction is at <a href="http://diydsp.blogspot.de/2014/12/javascript-audio-feature-extraction.html" rel="nofollow">http://diydsp.blogspot.de/2014/12/javascript-audio-feature-e...</a>
If you are into this, also check out Sonic Visualizer (<a href="http://www.sonicvisualiser.org" rel="nofollow">http://www.sonicvisualiser.org</a>), with its support for VAMP plug-ins for analyzing audio.