The music I listen to depends on my mood, and it enhances my mood.
For example, when I am up at 5:00 AM going hunting, I always have country playing. When I am sad, I also have country playing.
When I am getting crunk riding around or working out, its always rap. I can honestly lift more weight when I am listening to music that fires me up.
Some days I just feel like chilling, and put in some soft rock.
Music helps ENHANCE the mood I am in.
On rare occassions it completely changes it.