Harmonic minor and Phrygian dominant

The raised seventh in minor

A natural minor contains A, B, C, D, E, F and G. Raise G to G♯ and you get A harmonic minor: A–B–C–D–E–F–G♯.

The formula is 1–2–♭3–4–5–♭6–7. G♯ is a semitone below A and can act as a leading note. It also lets the chord on the fifth degree have a major third: E–G♯–B, or E7 when D is added.

The fifth mode finds a new centre

With E as the centre, the same notes give E Phrygian dominant: E–F–G♯–A–B–C–D. The formula becomes 1–♭2–3–4–5–♭6–♭7.

The minor second F sits close to E, while G♯ provides a major third. This combination of ♭2 and 3 distinguishes the sound from ordinary Phrygian, which has a minor third.

Distinguish function from modal colour

E7 can act as the dominant of A minor. E Phrygian dominant can then offer a scale colour over the dominant before the music returns home to A.

If E is instead sustained as the musical centre, you can explore the same notes modally. The harmonic experience is not automatically the same, even though the notes match.

F to G♯ is an augmented second: three semitones. Use the leap deliberately and also try phrases that connect it through the root E or the fourth A.

Limit the exploration to two differences

Start with A natural minor versus A harmonic minor, changing only G to G♯. Then compare E Phrygian with E Phrygian dominant, changing G to G♯ while keeping E as the centre. In the latter comparison, the third changes from minor to major.

Use one short phrase at a time and explain which note changes. This focused experiment shows the relationship without requiring you to learn every mode of harmonic minor at once.