The basis of harmonies in western music is the triad.
Triad = root + third + fifth
Can also be in root position - a
first inversion - b third in base
second inversion - c fifth in base
| Major | Minor (Harmonic) | |
| I | MAJ | MIN |
| II | MIN | DIM |
| III | MIN | AUG |
| IV | MAJ | MIN |
| V | MAJ | MAJ |
| VI | MIN | MAJ |
| VII | DIM | DIM |
Where: MAJ = major 3rd perfect 5th
MIN = minor 3rd perfect 5th
DIM = minor 3rd diminished 5th
AUG = Major 3rd augmented 5th

