Minor chords
The MINOR CHORD is the major chord's darker twin — sad, moody, serious.
Recipe: root, up a MINOR 3rd (3 semitones), then a MAJOR 3rd (4 semitones). It is the mirror of the major recipe: 3+4 instead of 4+3. Both end on the same perfect 5th.
A minor = A, C, E. Written "Am".
Only the middle note differs from the major chord — the 3rd is one semitone lower. That single semitone is the entire difference between happy and sad.
root + 3 + 4 semitones = 1 · ♭3 · 5
1
♭3
5
A minor: A–C–E.
Practise this in the trainer — it opens with this lesson the first time the concept comes up.