Sethares, William (2005). Tuning, Timbre, Spectrum, Scale, p.371. Springer Science & Business Media. ISBN9781852337971. "Harmonic entropy is a measure of the uncertainty in pitch perception, and it provides a physical correlate of tonalness ["the closeness of the partials of a complex sound to a harmonic series"], one aspect of the psychoacoustic concept of dissonance....high tonalness corresponds to low entropy and low tonalness corresponds to high entropy."
