The Pitch-class Integer Theorem

Mathematical music theory has assumed without proof that musical notes can be associated with the equivalence classes of ${\mathbb{Z}}_n$. We contest the triviality of this assertion, which we call the Pitch-class Integer Theorem (PCIT). Since the existing literature assumes the PCIT without proof, the mathematics to rigorously treat the PCIT does not yet exist. Thus, we construct an axiomatic proof of the PCIT to support the existing mathematical models of music theory.