harmonic series

A naturally-occurring set of frequencies that are all related to a single pitch, known as the “fundamental”. When a fundamental pitch is played, the note produced contains many different notes within the harmonic series. These additional notes are known as “partials” or “overtones”. It is also possible to bring out the sound of individual partials by playing them as harmonics. There is a consistent pattern of intervals between partials within the harmonic series, and these intervals become progressively smaller the further up the harmonic series they occur. For example, the interval between the first and second partials is an octave whereas the interval between the seventh and eighth partials is only approximately a major second. At the top end of the harmonic series, most partials are microtones. See also partial.