Changing Styles, Changing Corpora, Changing Tonal Models

This article explores the historical development of common-practice musical style and how that development might connect to the cognition of key within the history of Western European tonality. First, musical corpora of 19 composers were divided into three-chord progressions, and these progressions were tallied. The chord tallies were used for a cluster analysis and for measurements of inter-corpus cross entropy. The cluster analysis divided the corpora in ways that conform to historical and stylistic intuitions, and inter-corpus cross entropy was found to correlate with the years separating the corpora. These findings show that the chronological distance between two musical corpora seems to predict compositional similarity and that chord-progression norms are connected to specific historical situations. In order to model how these changes might affect the cognition of musical key, a corpus-sensitive key-finding algorithm was used to decode key within a famous example of musical ambiguity, the opening of Beethoven’s “Eroica” symphony. Each corpus-trained model created a slightly different key interpretation, suggesting that historically situated models of tonal cognition might indeed interpret the same stimulus differently.