Epistemologically, the theory of improvisational music therapy, distilled from the model Artistic Music Therapy used in the study: The effects of group improvisational music therapy on depression in adolescents and adults with substance abuse: A randomized controlled trial, is presented formally and linearly through six short propositions and their constituent inferences (corollaries) that connect, each proposition with a set of correspondence rules, to create a sequence to establish a relationship between the main propositions and their constitutive inferences.