In semiotics the neutral level of a sign is the "trace" left behind, the physical or material creation or remains of esthesic and poietic processes, levels, and analyses of symbolic forms. A part of all signs according to a tripartitional definition, it corresponds to Saussure's "sound-image" (or "signified", thus Pierce's "representamen").

Thus, "a symbolic form...is not some 'intermediary' in a process of 'communication' that transmits the meaning intended by the author to the audience; it is instead the result of a complex process of creation (the poietic process) that has to do with the form as well as the content of the work; it is also the point of departure for a complex process of reception (the esthesic proces that reconstructs a 'message.')" (Nattiez 1990, p.17)

Molino and Nattiez's diagram:

(ibid.)

An immanent description is an analysis of the neutral level (Nattiez 1990, p.75).

Source

• Nattiez, Jean-Jacques (1990). Music and Discourse: Toward a Semiology of Music (Musicologie générale et sémiologue, 1987). Translated by Carolyn Abbate (1990). ISBN 0691027145.