If the material is inspiring and motivates you, then it doesn't really matter what it is.
Oh! this opponent, this collaborator against your will, whose notion of beauty always differs from yours and whose means are often too limited for active assistance to your intentions!
I think it comes from really liking literary forms. Poetry is very beautiful, but the space on the page can be as affecting as where the text is. Like when Miles Davis doesn't play, it has a poignancy to it.