North American music theory's multifarious formalisms (Babbitt, Forte, Lewin, etc.) have sparked frequent critiques and reflections on the disciplinary outlook of music theory. More recent scholarship has introduced increasing nuance through examinations of the historical backgrounds of such thinking, drawing on information theory, computer science and analytical philosophy.

In particular, the consolidation of music theory in the US during the 1960s and 70s coincided with the emergence of the interdiscplinary assemblage known as ‘cognitive science'; connections with the Massachussettes Institute of Technology, a key site of this development, are documented for music theorists such as Forte, Lewin and Lerdahl. Consequently, formalist music theories inherited a certain epistemological outlook from this intellectual environment; however, this outlook is rarely made explicit and remains relatively underdiscussed in the literature.

I clarify this implicit epistemology through a case study of one particular strand of 1980s post-tonal theory: contour theory, which describes melodies in abstraction from measured interval and durations, instead focusing on relative order of events in pitch and time. While this approach taps into the abstract machinery of American twelve-tone theory and other postwar compositional techniques, Marvin (1987) and Quinn (1997) crucially also give it a psychological interpretation, providing "similarity measures" for contour.

Through a close reading of its theoretical texts on the background of contemporaneous discussions in cognitive science (e.g. Marr 1982 vs. Gibson 1979) and the analytical philosophy of mind (Fodor 1975, 1983), I show that the psychological interpretation of contour theory presupposes a computational perspective on perception that decouples listeners from their environment; this is notably at odds with more recent concerns about dynamics, embodiment, or motion in music, and also with longer-term trends in cognitive science since ca. 1990. This case study thus hopes to contribute to a historical contextualizaton of the enterprise of American post-tonal music theory.