I hate to point it out (I'm lying, I actually love pointing stuff like this out) but listening to any music will effect your mental state. It encourages the releasing of endorphins, can stabilise people's derotonin levels. There's a very good reason they recommend playing classical music to babies in the womb, along with using musical therapy to treat severe drug trip flashbacks.
I mean seriously, it's just common sense. Listen to something heavy and dark when you're in a bad mood and it reinforces your bad mood, listen to something soothing and light while you're working and your productivity increases. This sort of thing has been researched and investigated for years.
It's partly a placebo effect of course, since you listen to this music expecting drug-like effects, but really it's just someone who stumbled across the correct mixture of tones and sounds which provoke a major release of endorphins.
So yeah, I'm with the hysterical parents, we should ban all mood-altering chemicals that the brain produces naturally. We need to outlaw happines, sadness, love, hate, joy, anger. Yep, nothing more dangerous than human emotions.