The harmonic minor scale raises the 7th degree to create a leading tone and a stronger dominant chord

The natural minor scale dominant chord (chord v) is a minor triad, which produces a weak cadence back to the tonic. Classical musicians discovered that sharpening the 7th degree (making it a leading tone — only a semitone below the tonic) converts chord v (minor) to chord V (major), creating a much more conclusive V-i perfect cadence. This modified form is called the harmonic minor scale. The side effect is an augmented second (3 semitones) between the 6th and 7th degrees, giving the scale a distinctive exotic quality heard in Middle Eastern and Eastern European music.

Examples

A harmonic minor: A B C D E F G# A. The G# creates E major (V) rather than E minor (v). V-i in harmonic minor is E-Am — far more decisive than Em-Am.

Assessment

Play the natural and harmonic minor scales back to back and identify the changed note. Explain why the V-i cadence is stronger in harmonic minor than in natural minor.