Overtonal

Overtonal is an adjective used in acoustics and music theory to describe phenomena, theories, or practices that relate to the overtone series—the natural set of higher-frequency components that accompany a fundamental tone. Overtones are responsible for timbre and contribute to perceptual pitch, even when the fundamental is not carried by audible vibration.

In music theory and analysis, overtonal can refer to systems or approaches that organize pitch material according to the harmonic series rather than through equal temperament or other tunings. This usage may contrast with undertonal or subharmonic approaches, which emphasize lower partials or alternate tuning concepts. The term appears in discussions of tuning, harmony, and composition that foreground the influence of natural overtones on pitch relationships.

Applications and contexts include historical intonation practices that favor just intervals derived from the harmonic series, as well as modern spectral music, where composers analyze timbre and partials to inform pitch material and sonic color. In acoustics, overtonal considerations help explain phenomena such as vowel harmonics, instrument spectra, and voice timbres.

While not as common as overtone or harmonic-series terminology, overtonal is used to describe or analyze music and acoustics where the overtone structure is central to understanding pitch organization, timbre, or compositional method. See also: overtone, harmonic series, spectral music, just intonation, undertone.