You guys are dancing around with the wrong term. A piece can be both recognizable and derivative, and NOT be a copyright violation. (such as the last three words in that sentence) It is not recognizability that should be considered, but uniqueness when determining if a piece is derived from another original work. (clearly, those three words would not be sufficiently unique to be protected by copyright) Consider "uniqueness' and re-answer: the music chord; one polygon from a sphere; Frankensteining skullcaps; or making a 3D mold of another mesh, and the answers seem to divide themselves quite clearly.