Harmonic
A harmonic is a whole-number multiple of the fundamental frequency of a sound. It is an element of the harmonic series.
The timbre of a periodic sound, such as a bowed violin or the human voice, contains a nearly infinite amount of harmonic partials, starting with 1f, 2f, 3f, 4f... where f is the fundamental frequency. Each of these harmonics has a distinct amplitude, generally decreasing as the 'height' of the harmonic increases. The span between any two of these harmonics is a just interval. If the harmonics are numbered such that the fundamental is number 1, the octave is 2, etc., then the interval's ratio is given by the two numbers. For example the interval between the 3rd and 4th harmonics is 4/3.
The ancient Greeks called these harmonics "multiples", and considered them to be a unique interval class separate from superparticular and superpartient intervals.
A subharmonic is a unit fraction of the fundamental frequency of a sound. It is an element of the subharmonic series.
Individual pages
See Category: Harmonics.