I dig Seth Godin’s definition of art in “Linchpin”:
“Art is the intentional act of using your humanity to create a change in another person.”
In as few words as possible, the best definition I can come up with is: Art is transfered perception. When I write songs, I’m shooting for a shift in a listener’s thinking. Will they get what I’m feeling? Am I giving them my eyes? If not, then I’m just some clown, banging on a box of strings.