Interesting approach but a lot of songs I would consider falling into this category score very low:
Here are a few examples from the original reddit post[1]:
Song (Correlation)
The Velvet Underground - Heroin (2.95)
The Beatles - A Day In The Life (0.00)
Other songs with low correlation:
Lynyrd Skynyrd - Free Bird (0.38)
Metallica - Hero Of The Day (3.72), One(3.47)
I think the reason is that tempo and compression (which I associate with tension) are not taken into account but play a big part in our hearing experience. This data may be harder to extract, though. Anyway interesting work!
[1]: http://www.reddit.com/r/Music/comments/hnc3b/what_is_your_fa...