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: Music may be written in an enharmonic scale ( e.g. C minor , which only has four sharps in its key signature , compared to the eight flats required for D minor ) .