This chapter argues the roles of specific musical notations are more than incidental to their musical works; they serve to fix their identity, and provide a means with which to realise the work. It examines Michael Finnissy’s notational paradigms for their compositional and musical content. The other inscription system employed in musical work is what Finnissy terms ‘conventionally written material’, which is subject to the standard notational conventions associated with the standard notational paradigm. Nelson Goodman’s classification is dependent upon notational differentiation, in which the content of musical inscriptions, marks, and utterances, is unambiguous and fully determinate. For Goodman, the quality of being compliant is only attributable to structures which are notational; musical elements which are non-notational are by definition not capable of having a compliance-class, and as such cannot have compliants. Goodman’s ontology to admit that musical ideals specify not only specific notational systems and sub-systems, but also non-notational systems which are only indicated implicitly.