Harmonizing The Major Scale
To find the diatonic triads in a given key, build a triad on each scale degree using only notes from the key. Starting on each note, stack a 3rd and a 5th — but only use notes already in the scale.
Diatonic Triads in C Major
| Scale Degree | Root | 3rd | 5th | Triad |
|---|---|---|---|---|
| 1 | C | E | G | C Major |
| 2 | D | F | A | D Minor |
| 3 | E | G | B | E Minor |
| 4 | F | A | C | F Major |
| 5 | G | B | D | G Major |
| 6 | A | C | E | A Minor |
| 7 | B | D | F | B Diminished |
Quality Pattern
The pattern of triad qualities is the same in every key. It doesn't matter whether you're in C, F#, or B♠— the qualities always fall in the same order:
Major - Minor - Minor - Major - Major - Minor - Diminished