This study investigates the historical development of tonality in Western classical music, focusing on the concept of mode. Using a large dataset of approximately 13,000 MIDI-format pieces, two models—a geometric model and a Bayesian model—were developed to infer the number and characteristics of modes across different historical periods. The geometric model identifies the optimal number of modes, while the Bayesian model infers their characteristics. Results indicate four modes in the Renaissance, two (major and minor) in the Baroque and Classical eras, and no clear modal separation in the 19th century.

Daniel Harasim, Fabian C. Moss, Matthias Ramirez, Martin Rohrmeier