Recent work in computational and cognitive music theory has offered sophisticated accounts of tonal structure and musical syntax through generative grammars, probabilistic parsing, and implicit learning. While these approaches successfully describe hierarchical organization and stabilized analytical representations, they largely abstract away from the dynamic revision processes involved in real-time listening. As explicitly acknowledged in generative models of tonal syntax (e.g. Martin Rohrmeier), the retrospective reinterpretation of earlier musical events in light of later structural outcomes remains largely unformalized.

This paper proposes a conceptual framework for modeling retrospective musical cognition in late-eighteenth-century sonata form. Drawing on the goal-oriented logic of Sonata Theory (Elements of Sonata Theory), formal functions are treated as provisional syntactic hypotheses whose status is renegotiated when normative checkpoints—such as medial caesuras or cadential confirmations—are reached or fail. In this view, formal meaning emerges through postdictive reclassification, rather than purely forward parsing.

The framework is informed by cognitive theories of musical expectation and prediction (Sweet Anticipation), with the qualification that, in highly codified formal systems, prediction failure does not suppress mental representations but enables their functional re-evaluation. Retrospective reinterpretation thus operates less as error correction than as semantic reassignment within a normative syntactic system, where “false starts” and deformational outcomes are rhetorically controlled rather than ubiquitous. Beyond harmonic and formal functions, the model also accounts for the retrospective re-evaluation of schemata and rhetorical/topic cues, whose initial recognition may later be recontextualized by subsequent events.

To formalize this dynamic, the paper introduces a mechanism inspired by the logic of backpropagation—not as a learning algorithm, but as an error-driven retroactive update of latent functional representations. Later structural outcomes generate prediction errors that propagate backward, triggering reassignment of earlier formal interpretations rather than merely selecting among parallel forward parses. Building on rewrite-style update rules and error-modification principles drawn from the backpropagation literature, the framework sketches the possibility of a revision-based musical grammar that explicitly represents the temporal dynamics of reinterpretation, rather than encoding only a final stabilized parse.

Methodologically, the paper outlines a computationally tractable strategy based on multi-level temporal annotation and revision timelines, distinguishing between online plausible interpretations and stabilized retrospective analyses. By modeling how and where formal reinterpretations occur, this framework aims to bridge generative theories of musical syntax (A Generative Theory of Tonal Music), historical form theory, and contemporary cognitive accounts, offering a first step toward a formal theory of retrospective musical syntax.

• Huron, David. Sweet Anticipation: Music and the Psychology of Expectation. Cambridge, MA: MIT Press, 2006.
• Hepokoski, James, and Warren Darcy. Elements of Sonata Theory: Norms, Types, and Deformations in the Late-Eighteenth-Century Sonata. New York: Oxford University Press, 2006.
• Rohrmeier, Martin. “Towards a Generative Syntax of Tonal Harmony.” Journal of Mathematics and Music 5, no. 1 (2011): 35–53.
• Lerdahl, Fred, and Ray Jackendoff. A Generative Theory of Tonal Music. Cambridge, MA: MIT Press, 1983.
• Rumelhart, David E., Geoffrey E. Hinton, and Ronald J. Williams. “Learning Representations by Back-Propagating Errors.” Nature 323, no. 6088 (1986): 533–536.