chord

chord, in geometry

chord (kôrd), in geometry, straight line segment both end points of which lie on the circumference of a circle or other curve; it is a segment of a secant. A chord passing through the center of a circle is a diameter. In the same circle or in equal circles, equal chords subtend equal arcs and equal central angles.

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chord, in music

chord, in music, two or more simultaneously sounding pitches. In tonal music the fundamental chord is called the triad. It consists of three pitches, two a perfect fifth apart and a third pitch a major or minor third lower, forming respectively the major or minor triad. However, a triad may instead be diminished or augmented, or may contain dissonant elements such as a seventh. In atonal music, other types of chord formations occur. It is, however, an essential property of a chord that it be conceived as an entity, that its constituent notes "fuse" rather than merely coincide in time.

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chord

Grouping of three or more musical tones, especially as sounded simultaneously. The tones C-E–G constitute a “C major chord,” or “C major triad.” Chords may comprise any number of separate tones, and may be highly dissonant (see consonance and dissonance). The term harmony is often used loosely as a synonym.