The term
subharmonic is used in
music and
dynamics in a few different ways. In its pure sense, the term subharmonic refers strictly to any member of the subharmonic series (1/1, 1/2, 1/3, 1/4, etc.). When the subharmonic series is used to refer to frequency relationships, it is written with f representing some highest known reference frequency (f/1, f/2, f/3, f/4, etc.). The complex tones of acoustic instruments do not produce partials that resemble the subharmonic series. However, such tones can be produced artificially with audio software and electronics. Subharmonics can be contrasted with
harmonics. While harmonics can "...occur in any linear system", there are "...only fairly restricted conditions" that will lead to the "nonlinear phenomenon known as subharmonic generation." One way to define subharmonics is that they are "...integral submultiples of the fundamental (driving) frequency."