In Western music, we work with three different forms of the minor scales. The Natural Minor Scale is built using natural notes without any accidentals, and is classified as a purely diatonic scale.
In addition to the natural form, we have the Harmonic Minor and the Melodic Minor, each of which features a different sequence of whole tones and semitones. Notably, the Melodic Minor changes its structure between the ascending (going up) and descending (coming down) scales.
A Model Scale: A Minor
The A Natural Minor scale is our “model” scale because it has no sharps or flats in its key signature.
The sequence of Tones and Semitones, in the Natural minor is: T-S-T-T-S-T-T.
Because it follows this specific pattern of 5 Tones and 2 Semitones, without any leaps larger than tone, the Natural minor scale is Diatonic.
Harmonic Minor Scales
The Role of the Leading Tone
In Harmonic Minor scales, we notice that the leading tone (the 7th degree) is raised by a semitone. This is done to create an augmented second interval (three semitones) between the 6th and 7th degrees. The resulting half-step between the leading tone and the tonic creates a strong gravitational pull, a sense of finality and resolution, moving the listener toward the “home” note.
Melodic Minor Scales
In Melodic Minor scales, this wide three-semitone gap is removed to make the melody smoother. However, the most unique feature here is the changing structure:
- Ascending: The 6th and 7th degrees are raised to lead smoothly toward the tonic.
- Descending: The scale reverts to the natural minor pattern (lowering the 6th and 7th) as the strong toward the tonic is no longer needed when moving away from it.
The Sequence of Minor Scales
Just like Major scales, the order of Minor scales follows a specific mathematical pattern of intervals.
Minor Scales with Sharps
The minor scales with sharps are: E, B, F#, C#, G#, D#, and A#.
- What do we notice? Starting from our model (A Minor), the first scale with a sharp is E Minor, which is a Perfect 5th higher. Each subsequent scale in the sequence is also a Perfect 5th above the previous one.
Minor Scales with Flats
The minor scales with flats are: D, G, C, F, Bb, Eb, and Ab.
- What do we notice? Starting from A Minor, the first scale with a flat is D Minor, which is a Perfect 4th higher (or a Perfect 5th lower). Each following scale in the sequence is a Perfect 4th away from the last.
Enharmonic Minor Scales
Just like the Major scales, there are 15 minor scales in total. Even though there are only 12 unique pitches in an octave, we have 15 scales because three of them are Enharmonic. These are scales that are written differently but sound exactly the same.
The three pairs of Enharmonic Minor Scales are:
- G# Minor and Ab Minor
- D# Minor and Eb Minor
- A# Minor and Bb Minor