Casual Property is the idea that there's things we can own, without having to actually hold them. Things like ideas, pretty pictures we have drawn, sounds we made.
My punk sensibilities rebel against such concepts. You should only be able to own what you can hold. Musicians who record their work deny the truth of the art that is song, which is the magic of the interaction between performer and audience. Recorded music is Casual Property, a false image of something real.