Passions are things which take hold of you and turn you away from God, at least that is what I think. (I don't know if that is the Orthodox definition!) - so a passion for music that wasn't from God say, would produce music that rather than inspiring people or gladdening their heart or stirring up some positive response, would at the best leave a listening either with no feeling, or upset/angry/annoyed/negative.
Rsskiya - when I was at Uni, a time when I had no interest in religion as such but some vague wishy-washy notion of god, I once joked to a Christian friend that if I ever became Christian, it would only be as an Orthodox Christian. God must have heard me, and taken me at face value.