Music and emotions

I find the causal relationship between my emotional state and the music I listen to very interesting.  I know that music can elicit emotion, however I find that my emotions tend to do drive my choice in music.  Basically I’ve already determined how I “want” to feel and I’m choosing music that reinforces those emotions (usually negative).  Why is it so hard to want to feel happy?  Guilt?  Regret?  Ummm, yes and yes.