One most often encounters chords from the parallel minor key used in a major key. It is more accurate to say that the major scale of the key expands its resources by adding the three variant notes of the parallel minor scale. This process is often called mode mixture, or mixture for short. It is one of the most important and frequently used chords that is created by mixture. It is the lowered or flatted mediant.
Secondary mixture occurs when the third of a chord is altered by a means other than normal mixture.
A very frequent example is in the major mode, as a major triad. The approach to this chord is often with , mimicking the sound of the Phrygian cadence. Dominants Some accidentals arise from the used of an applied chord. See HVL Chapter 25, Applied V and VII . The note with an accidental will be a half-step below the root of the diatonc chord.