In what way does music affect people?

A bit of inquiry:
Does the music you listen to affect the way you view world, or
Does the way you view the world affect what music you listen to, or both?

For example, people with fundamentalist christian beliefs tend to listen to only christian music, whether it be rock, choir, metal, pop or whatever. And every other kind of music is the makings of the devil. At least that I'm sure of.

But then there are people with less radical beliefs and views, who expose themselves to various kinds of music their friends listen to, what the radio plays, what they hear at clubs and parties etc, and who really don't have a big preference.

In the case of the former example, it's quite clear that the person's worldview defines what that person listens to. And the latter person may still be susceptible to having his/hers views shaped by the influences he/she gets through the medium of music. Or, that person just has so stable view of the world that whatever he listens to doesn't affect his beliefs in any way, but the music simply gets filtered through his worldview.

What do you think is the right way, or is there any, and what other factors need to be taken into consideration when approaching this subject?

Also what do you think/know are some other ways music can have an affect on our being - whether on a physical, mental, emotional or spiritual level?