Chromatic chords become meaningful only in context (follow the links in the blue triangle to progressions involving chromatic chords), but in general terms they fall into three broad categories:

1. diatonic triads in which one of the notes has been raised or lowered by a semitone to a non-diatonic note (e.g. a C major chord with a G sharp instead of a G natural - see augmented fifth)
2. diatonic triads to which a chromatic note has been added (e.g. chord vii in C major with an added A flat - see diminished seventh)
3. triads which are from a different diatonic scale to that which the passage is based on (e.g. a D flat major triad in a passage in C major - see see Neapolitan)

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