consonanceI

ConsonanceI is an algorithmic framework developed for the analysis and generation of consonant harmonic structures within polyphonic music. It was first released by the Institute of Music Informatics in 2019 under the designation Consonant Harmony Analysis, Version I. The system combines rule‑based modeling of just intonation and temperamental tuning with machine‑learning techniques to evaluate the consonance level of chords and melodic lines.

The core of ConsonanceI is a scoring function that assigns a numerical value to a set of pitches based on the Roman numeral theory of harmonic function, the frequency ratios of intervals, and perceptual salience models. This allows composers and researchers to quantify how well an arbitrary chord satisfies classical consonance criteria. In addition, the algorithm can iterate over a given musical texture to highlight segments with the highest consonance scores and can suggest alternative voicings that preserve melodic intent while improving harmonic quality.

ConsonanceI has been incorporated into several music education platforms, providing students with instant feedback on the consonant properties of their compositions. It has also appeared in academic studies examining the evolution of tonal harmony across western music, and it has been cited in journals of music theory and computer music. The software is available under an open‑source license, enabling researchers to extend its interval evaluation modules and to adapt the scoring model to non‑western tuning systems.