If you didn't click the link, I'll paraphrase. Basically the article finds that Heavy Metal causes stress, which is bad for your heart. Apparently the best music for your heart is "John Denver country-style."
Scientists asked 10 non-smokers to avoid listening to their favorite music. Then, these volunteers rocked out to the controlled samples. The study found..."that volunteer's arteries opened 26% wider on average during music they liked but narrowed by 6% when 'anxious' music was played."
The problem here, of course, is that there is no regard for human emotion. Fast music just might make your heart rate speed up a little. I don't think this is necessarily a bad thing. Also, I don't like John Denver. I could guess that listening to him for a long time would stress me out - thus causing my arteries narrow.
I get crazy over silly medical studies that demonize Metal. I think the article forgets most of the facts, so I don't want to unfairly judge the study. Still, I find it hard not to scream "give me a break" at the top of my lungs to anyone that will listen.