 For the symbol system also to be notational, more than syntactic disjointness and finite differentiation is required. Symbol systems are notational when 1) the characters are correlated to the field of reference unambiguously (with no character being correlated to more than one class of reference, or “compliance class”), 2) what a character refers to—the compliance class—must not intersect the compliance class of another character (i.e., the characters must be semantically disjoint), and 3) it is always possible to determine to which symbol an item in the field of reference complies (i.e., the system must be, semantically, finitely differentiated).With exceptions that will have to be spelled out below, a musical score in standard Western notation is a character in a notational system. Natural languages like the English language have a notational scheme but fail to be notational systems, because of ambiguities (in English, “cape” refers to a piece of land as well as to a piece of clothing) and lack of semantic disjointness (“man” and “doctor” have some referents in common). Finally, pictorial systems fail on both syntactic and semantic grounds.