Which minor scale is defined by lowered 3rd, 6th, and 7th?

Which minor scale is defined by lowered 3rd, 6th, and 7th?

• A. Harmonic minor
• B. Melodic minor
• C. Major
• D. Natural minor

Answer: (D)

Understanding how minor scales differ by which degrees are lowered or raised helps identify this one. In natural minor, the 3rd, 6th, and 7th scale degrees are flattened relative to the major scale of the same tonic. So the natural minor has the pattern 1, b3, 4, 5, b6, b7, 1. For example, in the key of A: natural minor is A B C D E F G A. Compare that to the A major scale (A B C# D E F# G# A) and you can clearly see the 3rd (C vs C#), the 6th (F vs F#), and the 7th (G vs G#) are lowered. Harmonic minor keeps the 3rd and 6th as in natural minor but raises the 7th to create a leading tone (A B C D E F G# A). Melodic minor raises both the 6th and 7th when ascending (A B C D E F# G# A) but reverts to natural minor when descending. The major scale has none of these alterations. So the scale defined by lowering the 3rd, 6th, and 7th is natural minor.

Understanding how minor scales differ by which degrees are lowered or raised helps identify this one. In natural minor, the 3rd, 6th, and 7th scale degrees are flattened relative to the major scale of the same tonic. So the natural minor has the pattern 1, b3, 4, 5, b6, b7, 1.

For example, in the key of A: natural minor is A B C D E F G A. Compare that to the A major scale (A B C# D E F# G# A) and you can clearly see the 3rd (C vs C#), the 6th (F vs F#), and the 7th (G vs G#) are lowered.

Harmonic minor keeps the 3rd and 6th as in natural minor but raises the 7th to create a leading tone (A B C D E F G# A). Melodic minor raises both the 6th and 7th when ascending (A B C D E F# G# A) but reverts to natural minor when descending. The major scale has none of these alterations.

So the scale defined by lowering the 3rd, 6th, and 7th is natural minor.