A dissonance score is a time-series graph showing how sensory dissonance ebbs and flows throughout a musical performance

A dissonance score is a time-series graph of the total sensory dissonance of all simultaneously sounding notes and their partials in a musical performance. It is computed by: partitioning a recording into short time segments; for each segment, identifying all sounding pitches and their spectra; computing the pairwise dissonance between all partials; summing to get a total dissonance value; plotting the result over time. The resulting graph shows the ebb and flow of musical tension in perceptual terms, independent of tonal analysis. Dissonance scores can be used to: compare different performances of the same piece; analyze music without a written score; investigate how tuning systems affect a piece’s dissonance profile; and examine non-Western music using a culture-neutral psychoacoustic measure.

Examples

Dissonance score of Scarlatti K380: shows the four-repetition I-V motif as four small hills, the developmental section as higher dissonance, and resolution to the tonic as low dissonance. Applied to Balinese gamelan: shows dissonance peaks at structural boundaries. Applied to Thai Lam Sithandon: shows dissonance rising as more instrument layers enter, falling at points of structural unison.

Assessment

A musician claims two different performances of the same Brahms sonata ‘feel different in terms of tension and release.’ How could dissonance scores help evaluate this claim objectively? What information does a dissonance score provide that a conventional music theory analysis does not?