Original: While this definition encompasses many scales and modes such as Dorian mode and the Phrygian mode , the term in its stricter sense is usually limited to the natural minor , harmonic minor , and melodic minor scales , described below , which are in most common use in Western classical music ( see major and minor ) .
Simplified: These are the diminished seventh chord ( 2nd , 4th , 6th and 7th degrees ) and the augmented chord ( the 3rd , 5th and 7th degrees ) .