Unison word meaning and definition

[noun] (music) two or more sounds or tones at the same pitch or in octaves; "singing in unison"
[noun] occurring together or simultaneously; "the two spoke in unison"
[noun] corresponding exactly; "marching in unison"

\U"ni*son\ (?; 277), n. [LL. unisonus having the same sound; L. unus one + sonus a sound: cf. F. unisson, It. unisono. See {One}, and {Sound} a noise.] 1. Harmony; agreement; concord; union. 2. (Mus.) Identity in pitch; coincidence of sounds proceeding from an equality in the number of vibrations made in a given time by two or more sonorous bodies. Parts played or sung in octaves are also said to be in unison, or in octaves. Note: If two cords of the same substance have equal length, thickness, and tension, they are said to be in unison, and their sounds will be in unison. Sounds of very different qualities and force may be in unison, as the sound of a bell may be in unison with a sound of a flute. Unison, then, consists in identity of pitch alone, irrespective of quality of sound, or timbre, whether of instruments or of human voices. A piece or passage is said to be sung or played in unison when all the voices or instruments perform the same part, in which sense unison is contradistinguished from harmony. 3. A single, unvaried. [R.] --Pope. {In unison}, in agreement; agreeing in tone; in concord.
\U"ni*son\ (?; 277), a. [Cf. It. unisono. See {Unison}, n.] 1. Sounding alone. [Obs.] [sounds] intermixed with voice, Choral or unison. --Milton. 2. (Mus.) Sounded alike in pitch; unisonant; unisonous; as, unison passages, in which two or more parts unite in coincident sound.

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