overtone

/oh"veuhr tohn'/, n.

1. Music. an acoustical frequency that is higher in frequency than the fundamental.

2. an additional, usually subsidiary and implicit meaning or quality: an aesthetic theory with definite political overtones.

[1865-70; trans. of G Oberton. See OVER-, TONE]

Syn. 2. insinuation, suggestion, intimation, hint.

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In acoustics, a faint higher tone contained within almost any musical tone.

A body producing a musical pitch

such as a taut string or a column of air within the tubular body of a wind instrument

vibrates not only as a unit but simultaneously also in sections, resulting in the presence of a series of overtones within the fundamental tone (i.e., the one identified as the actual pitch). Harmonics are a series of overtones resulting when the partial vibrations are of equal sections (e.g., halves, thirds, fourths). Partials are nonharmonic overtones

that is, tones the frequencies of which lie outside the harmonic series. Overtones contribute greatly to the timbre of a given sound source, even though few listeners are aware of hearing any pitch except the fundamental. There are a few rare examples of the human voice creating overtones, notably in the chants of the Tibetan monks and the songs of the Tuvan throat singers. The latter can sometimes produce two overtones.

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▪ acoustics

      in acoustics, tone sounding above the fundamental tone when a string or air column vibrates as a whole, producing the fundamental, or first harmonic. If it vibrates in sections, it produces overtones, or harmonics. The listener normally hears the fundamental pitch clearly; with concentration, overtones may be heard.

      Harmonics are a series of overtones resulting when the frequencies are exact multiples of the fundamental frequency. The frequencies of the upper harmonics form simple ratios with the frequency of the first harmonic (e.g., 2:1, 3:1, 4:1). In the case of ideal stretched strings and air columns, higher harmonics result when the full length of the vibrating medium is divided into more and more equal parts.

      Some musical (music) instruments (musical instrument)—among them those whose sounds result from the vibration of metal, wood, or stone bars (e.g., marimbas or xylophones); of cylinders (e.g., orchestral chimes); of plates (e.g., cymbals); or of membranes (e.g., drums)—produce nonharmonic overtones—that is, the frequencies of the overtones are not multiples of the fundamental frequency.

      Musical timbre, or tone colour, is affected by the particular overtones favoured by a given instrument. The “woody” sound of the clarinet comes from its emphasis on low-frequency odd harmonics, whereas the more nasal sound of the oboe comes from the presence of all harmonics and a greater emphasis on the higher frequencies.

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