Harmonic usually refers to the frequency components of a time-varying signal, such as a musical note.

Mathematics, science and engineering Harmonic (mathematics), a number of concepts in mathematics Harmonic analysis, representing signals by superposition of basic waves Harmonic oscillator, a concept in classical mechanics Simple harmonic motion, a concept in classical mechanics Harmonic distortion, a measurement of signal distortion Harmonics (electrical power) Harmonic series (mathematics), a divergent infinite series Harmonic tremor, a rhythmic earthquake which may indicate volcanic activity

Music String harmonic, a string instrument playing technique Artificial harmonic, a string instrument playing technique Enharmonic, a "spelling" issue in music Harmonic series (music), the series of overtones (or partials) present in a musical note, or the vibrational modes of a string or an air column Scale of harmonics, a musical scale based on harmonic nodes of a string The Harmonics, a rock a cappella group from Stanford University Harmony, the musical use of simultaneous pitches, or chords Inharmonicity, the degree of overtones' departure from integral multiples of the fundamental frequency Overtone, any resonant frequency higher than the fundamental frequency

Other uses Harmonic (color), a relationship between three colors Harmonic Convergence, a New Age astrological term "Harmonics", the twelfth movement of Mike Oldfield's Tubular Bells 2003 album Harmonic Inc., a video infrastructure product company, headquartered in San Jose, California Harmonic (company), an artificial intelligence-based mathematics company

See also Harmonix, a video game development company