Harmonic
A harmonic of a wave is the part of a signal's frequency that is a whole multiple (an integer) of the fundamental frequency. The fundamental frequency is the lowest frequency of a periodic waveform. If f is the fundamental frequency (that is, 1f), then the harmonics have frequencies 2f, 3f, 4f..., and so on. The second harmonic (2f) has a frequency twice that of the fundamental frequency, the third harmonic three times, and so on. This concept applies to wave motions of any form of energy, but is most often related to acoustics.
Frequencies that lie between one harmonic and another harmonic are called interharmonics. For example, 11⁄3f is an interharmonic between the fundamental frequency (or first harmonic) and the second harmonic. Interharmonics is a term invented, or at least standardised, by the international electronics industry about 1999, particularly for use in electrical energy. However, interharmonic frequencies also occur naturally in other radiant energies, for example music or any type of sound.
Harmonic Media
- Cello natural harmonics.png
Two different notations of natural harmonics on the cello. First as sounded (more common), then as fingered (easier to sightread).
- Pipe001.gif
fundamental tone or 1st harmonic
- Molecule1.gif
fundamental tone or 1st harmonic*random molecular representation
- Pipe002.gif
1st overtone or 2nd harmonic
1st overtone or 2nd harmonic*random molecular representation
- Pipe003.gif
2nd overtone or 3rd harmonic
- Molecule3.gif
2nd overtone or 3rd harmonic*random molecular representation
- Pipe004.gif
3rd overtone or 4th harmonic
- Molecule4.gif
3rd overtone or 4th harmonic*random molecular representation
