Seven notes, built from a pattern of whole steps (W) and half steps (H):

W — W — H — W — W — W — H

Key	Notes
C	C D E F G A B
G	G A B C D E F#
D	D E F# G A B C#
A	A B C# D E F# G#
E	E F# G# A B C# D#
B	B C# D# E F# G# A#
F# / Gb	F# G# A# B C# D# E#
F	F G A Bb C D E
Bb	Bb C D Eb F G A
Eb	Eb F G Ab Bb C D
Ab	Ab Bb C Db Eb F G
Db	Db Eb F Gb Ab Bb C

W — H — W — W — H — W — W

Or: take the major scale and lower the 3rd, 6th, and 7th.

Raises the 7th of the natural minor to create a leading tone — a strong pull toward the root.

Raises both the 6th and 7th of the natural minor, smoothing out the augmented-second gap in harmonic minor.

Each note in a scale has a numbered position:

Degree	Name
1	Root (tonic)
2	Supertonic
3	Mediant
4	Subdominant
5	Dominant
6	Submediant
7	Leading tone (major) / Subtonic (natural minor)

• The major scale is the reference point for everything — intervals, chords, modes, and all three minor scale forms are described relative to it.
• Natural minor is what people mean when they say "minor scale" without specifying.
• Every major key has a relative minor that shares its key signature, starting on the 6th degree.