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.
The Columbia Electronic Encyclopedia, 6th ed. Copyright © 2012, Columbia University Press. All rights reserved.