First the usual disclaimer, I’m not affiliated with any of the folks who created this stuff. 
Excellent program for analyzing audio. If you ever wanted to look at the “guts” of an audio recording, this program is what you need. VS has helped me to see how the sounds I create interact at fundamental levels. Using the analysis information, I’ve been able to correct some “bad sonic habits” I’ve formed in my ambient compos. It’s easy to use and there are good docs and videos available.
http://www.sonicvisualiser.org/
and here’s the more part:
VAMP plugins work with both VS and Audacity to extend even further their analysis capabilities. Check out this link for downloadable VAMP plugins. I think you’d be amazed at what you can learn from your music.
http://www.vamp-plugins.org/download.html
Oh, did I mention both VS and VAMP are free? 
Cheers.