ALTERATION

n. modification, change; correction, adjustment

In music alteration, an example of chromaticism, is the use of a neighboring pitch in the chromatic scale in place of its diatonic neighbor such as in an altered chord. This should not be confused with borrowing (as in borrowed chord), in which pitches or chords from the parallel key are used in place of those of the original key. Altered notes may be used as leading tones to emphasis their diatonic neighbors. For example, an altered dominant or V chord may be Gb-B-D#: See alsoDiatonic and chromatic
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Noun
1. an event that occurs when something passes from one state or phase to another; "the change was intended to increase sales"; "this storm is certainly a change for the worse"; "the neighborhood had undergone few modifications since his last visit years ago"
(synonym) change, modification
(hypernym) happening, occurrence, natural event
(hyponym) avulsion
(derivation) change, alter, modify
2. the act of making something different (as e.g. the size of a garment)
(synonym) modification, adjustment
(hypernym) change
(hyponym) loosening, laxation
(derivation) change, alter, modify
3. the act of revising or altering (involving reconsideration and modification); "it would require a drastic revision of his opinion"
(synonym) revision
(hypernym) transformation, translation
(hyponym) distraction, misdirection

n. alteration, inflection; distortion

(n.)
The state of being altered; a change made in the form or nature of a thing; changed condition.
  

(n.)
The act of altering or making different.