Grundtons

Grundtons (singular Grundton) are fundamental tones that occupy a central place in both acoustics and music theory. The term encompasses at least two closely related meanings: the lowest vibrating frequency produced by a sound source, and the root or tonic pitch in a musical context.

In acoustics and psychoacoustics, the Grundton is the fundamental frequency f0 that underpins the overtones or harmonic series. The spectrum contains higher partials at integer multiples of f0, and the relative strengths of these components shape timbre. Perceptually, listeners often hear the Grundton as the pitch of the sound, and in some cases the so-called missing fundamental phenomenon can lead to the perception of the Grundton even when it is physically absent.

In music theory, Grundton also denotes the root note of a scale or chord—the pitch that determines the tonal center and harmonic function. Chords are frequently described by their Grundton (for example, a C major chord has C as its Grundton). The concept underpins tuning, modulation, and harmonic analysis, and is closely linked to the tonic in functional harmony.

In practice, the term appears in German-language literature and is sometimes translated as fundamental tone or root, depending on context. The identification of Grundtons is fundamental in pitch detection, instrument design, and digital sound processing.

See also: fundamental frequency, harmonic series, root note, tonic, timbre, pitch detection.