Guitar chords

Chord, in music, three or more single pitches heard simultaneously. Depending on the harmonic style, chords may be consonant, implying repose, or dissonant, implying subsequent resolution to and by another chord. In traditional Western harmony, chords are formed by superimpositions of intervals of a third. Thus, the basic triad results from the superimposition of two conjunct thirds encompassing the interval of a fifth; for example, e–g (a minor third) superimposed on c–e (a major third) yields the triad c–e–g. Superimposition of an additional third produces a seventh chord, for example, c–e–g–b or c–e–g–b♭ (c–b and c–b♭ are, respectively, major and minor sevenths); a further third expands the seventh chord to a ninth chord (c–e–g–b–d′). In Western art music of the late 19th century, seventh and ninth chords, serving as expressive reinforcements of basic harmonic functions, often replaced the triad altogether.