Questions: Comparing Natural, Harmonic, and Melodic Minor

Question 1

A composer writing in A minor needs to harmonize a cadence with maximum gravitational pull toward the tonic. Which scale form provides the necessary leading tone?

• A. Natural minor — it contains the authentic minor sound that defines the key
• B. Harmonic minor — it raises the seventh scale degree to create a leading tone and a major dominant chord
• C. Melodic minor — it provides the smoothest melodic motion toward the tonic
• D. Any minor scale works equally well for cadences — the choice is purely stylistic

Answer: (B)

Strong cadential pull depends on the leading tone — scale degree 7 sitting a half-step below the tonic. Natural minor has a lowered seventh, making the dominant chord minor (weak pull). Harmonic minor raises the seventh, restoring the leading tone and making the dominant major or dominant-seventh — creating powerful cadential motion. This is exactly why it's called 'harmonic' minor: it was developed to solve the harmonic problem of weak cadences in natural minor.

Question 2

A singer performing a minor-key melody that ascends stepwise toward the high tonic finds an awkward, wide interval using harmonic minor. What causes it, and how does melodic minor address it?

• A. The leading tone is too high, so melodic minor lowers the seventh to fix the range
• B. The raised seventh creates an augmented second between b6 and the raised 7, which is melodically awkward; melodic minor also raises the sixth to eliminate this gap
• C. Harmonic minor has too many sharps, so melodic minor reduces them for ease of performance
• D. There is no awkward interval in harmonic minor — the augmented second only occurs when descending

Answer: (B)

Harmonic minor's fix — raising the seventh — creates an augmented second (three semitones) between the lowered sixth (b6) and the raised seventh. This is harmonically powerful but melodically ungainly, especially in vocal writing. Melodic minor addresses this by also raising the sixth, creating a smooth stepwise ascent that matches the major scale's upper tetrachord. When descending, the leading-tone pull is no longer needed, so both alterations are dropped.

Question 3

Harmonic minor raises only the seventh scale degree compared to natural minor, and this creates an augmented second interval between the sixth and seventh degrees.

• T. True
• F. False

Answer: True

Natural minor has b6 and b7. Harmonic minor raises b7 to the natural seventh (the leading tone), leaving b6 unchanged. The interval between b6 and the natural 7 spans three semitones — an augmented second. This is what makes harmonic minor melodically awkward for ascending lines but harmonically useful for cadential progressions where strong dominant-to-tonic resolution is needed.

Question 4

Melodic minor uses raised sixth and seventh scale degrees in both ascending and descending directions.

• T. True
• F. False

Answer: False

Melodic minor uses raised sixth and seventh only when ascending toward the tonic, where the leading tone's pull is needed and smooth stepwise motion matters most. When descending away from the tonic, the leading-tone drive is no longer needed, so both alterations are dropped and the scale reverts to natural minor. The asymmetry — different notes ascending and descending — is the defining feature of melodic minor, directly reflecting its functional purpose.

Question 5

Why do three different minor scale forms exist rather than a single universal minor scale?

Model answer: Three forms exist because no single minor scale simultaneously satisfies all musical needs. Natural minor captures the authentic minor color but lacks a leading tone, giving it weak dominant-to-tonic cadential motion. Harmonic minor fixes the cadential problem by raising the seventh but creates an awkward augmented second in melodic lines. Melodic minor fixes the melodic awkwardness by also raising the sixth ascending while reverting to natural minor descending. Each form is a solution to a different tension between harmonic function and melodic smoothness.

The three forms coexist within a single piece rather than competing. A composer might use a harmonic minor dominant chord at a cadence, a natural minor sixth degree in a melody, and a melodic minor passage when a line ascends to the tonic — sometimes within the same phrase. Understanding which form is active at any moment requires knowing whether the context is primarily harmonic (cadential) or melodic (linear motion), and whether the line is ascending or descending.