A single pitch or frequency in the harmonic series, which varies in pitch according to the pitch of the fundamental but is always a consistent interval above the fundamental according to its number in the harmonic series. For example, the second partial is an octave above the fundamental, the third partial is an octave and a fifth above the fundamental, and the fourth partial is two octaves above the fundamental. Also known as simply a “harmonic” or “overtone”, although when described as an overtone it has a different number, as the first overtone is the same as the second partial. See also harmonic series.