Minor Scale Formation

In music theory minor scales means three scales pattern or three type of scale.

1) Normal minor scale

2) Harmonic minor scale

3)Melodic minor scale

Minor scale have unique relations with the major scale, that is called relative minor. In Staff notation relative major and minor scale share same key signature.
To build a minor scale go to the 6th note of the major scale and start to build 8 note scale from that note, you can get the 6th note of a major scale either going 6th step up or ascending from the tonic or root note or 2 steps down or descending.
So C major scale and Am minor scale share same key signature, G major scale and E minor scale share same key signature.
Natural Minor Scale
Natural minor scale is a diatonic scale that is built by starting from 6th note of its relative major scale.
So A is relative minor of C major and conversely C major is relative major of A
minor. Every major scale has a relative minor, which start from the 6th note or 6th step of any major scale.

Example - 6th note of F major scale is D

So F major relative minor is Dm

Natural Minor Scale Formula

1-2 - Full Tone or Whole Step
2-3 - Semi Tone or Half Step
3-4 - Full Tone or Whole Step
4-5 - Full Tone or Whole Step
5-6 - Semi Tone or Half Step
6-7 - Full Tone or Whole Step
7-8 - Full Tone or Whole Step

C Natural Minor Scale

Harmonic Minor Scale

The harmonic minor scale has the same notes as the natural minor scale except that the seventh note is raised by one semitone or half step up, create augmented second between the sixth and seventh note. Harmonic minor scale 7th to 8th note is leading tone the tonic because it is a semitone lower than the tonic, in natural minor scale whole tone lower than the tonic.

Harmonic Minor Scale Formula

C Harmonic Minor Scale

Melodic Minor Scale

The melodic minor scale is a combination of natural minor and harmonic minor scale. In melodic minor scale the ascending and descending are different.
Ascending Melodic Minor Formula

1-2 - Full Tone or Whole Step
2-3 - Semi Tone or Half Step
3-4 - Full Tone or Whole Step
4-5 - Full Tone or Whole Step
5-6 - Full Tone or Whole Step
6-7 - Full Tone or Whole Step
7-8 - Semi Tone or Half Step

Descending Melodic Minor Formula

Descending melodic minor scale formula as same as normal minor scale formula.
1-2 - Full Tone or Whole Step
2-3 - Semi Tone or Half Step
3-4 - Full Tone or Whole Step
4-5 - Full Tone or Whole Step
5-6 - Semi Tone or Half Step
6-7 - Full Tone or Whole Step
7-8 - Full Tone or Whole Step

C Melodic Minor Scale

Minor Scale Formation