In
music, an altered chord, an example of
alteration, is a chord with one or more
diatonic notes replaced by, or altered to, a neighboring pitch in the
chromatic scale. For example the following progression: uses an altered IV chord and is an alteration of: The Ab serves as a
leading tone to G. In
jazz music, an altered chord is a dominant
chord that has the 5th and the 9th raised or lowered by a single semi-tone. An altered chord may contain any of the following:b5#5b9#9
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