Aeolian mode

The Aeolian mode is built on the sixth degree of the major scale — all white keys from A to A on the piano. It is identical to the natural minor scale and serves as the foundation for minor-key music in all Western traditions. Its characteristic intervals — a minor third, minor sixth, and minor seventh above the tonic — create the dark, melancholic quality universally associated with minor keys. While the harmonic and melodic minor scales modify the Aeolian mode for functional harmonic purposes (raising the seventh to create a leading tone), the pure Aeolian mode remains the default minor sound in popular music, folk music, and much contemporary composition. Songs in "minor key" in pop and rock are almost always Aeolian. The mode's lack of a leading tone gives it a more "natural" and less driven quality than harmonic minor, which is why it dominates in styles that prioritize mood and atmosphere over Classical-era harmonic function.