Building chords: triads
Build a major or minor triad from any note by counting half steps, read simple chord symbols, and work out the seven chords that live inside C major.
THREE NOTES
The triad: root, third, fifth
A triad is a three-note chord made by stacking two thirds. The bottom note is the root and gives the chord its name. A third above it sits the third. A third above that sits the fifth, so called because it is a fifth above the root.
On the white keys the recipe is: play one, skip one, play one, skip one, play one. Start on C and you get C, E, G.
The C major triad, measured in half steps from the root.
note: C C# D D# E F F# G
half steps: 0 1 2 3 4 5 6 7
^ ^ ^
root third fifthC major = C E G = root, +4, +7
Bottom third C-E: 4 (major). Top third E-G: 3 (minor).4 + 3 = 7. A major third with a minor third on top always adds up to a perfect fifth.
Major and minor triads
A major triad is root + major third (4 half steps) + perfect fifth (7). A minor triad is root + minor third (3 half steps) + perfect fifth (7). The root and fifth are the same in both. Only the middle note moves, by one half step.
C major: C E G (0, 4, 7). C minor: C Eb G (0, 3, 7). In chord symbols a letter alone means major, and a small m means minor: C and Cm.
Check yourself
Nika wants to play an A minor chord (Am). Counting from A, which three notes does she need?
- A, C#, E
- A, B, C
- A, D, E
- A, C, E
Show the answer
A, C, E
Yes. Three half steps above A is C (A#, B, C), and seven above A is E. Root, +3, +7.
One half step, two moods
C · C E G
Major third at the bottom (4), minor third on top (3). Sounds bright, open, settled. This is the sound of the last chord of most cheerful songs.
Cm · C Eb G
Minor third at the bottom (3), major third on top (4). Sounds darker, more inward. The outside notes have not moved at all. Only E slid down to Eb.
Check yourself
To turn a major triad into a minor triad, you lower all three notes by a half step.
Show the answer
False
Lowering all three just gives you the same major chord a half step lower. To go from major to minor you lower only the third: C E G becomes C Eb G. The root and the fifth stay where they are.
A FAMILY OF SEVEN
The chords inside a scale
Take the C major scale and build a triad on each of its seven notes, using only notes of the scale: play one, skip one, play one, skip one, play one. You never touch a black key, yet the chords do not all come out major. The uneven spacing of the white keys decides for you.
From C you get C E G, with 4 half steps at the bottom: major. From D you get D F A, with only 3 at the bottom, because E–F is a half step: minor.
Triads on each note of C major (white keys only).
The numbers are the two stacked thirds, in half steps.
C E G 4 + 3 C major
D F A 3 + 4 Dm minor
E G B 3 + 4 Em minor
F A C 4 + 3 F major
G B D 4 + 3 G major
A C E 3 + 4 Am minor
B D F 3 + 3 Bdim diminished3 major chords: C F G
3 minor chords: Dm Em Am
1 diminished: BdimThe odd one out is B D F. Two minor thirds add up to only 6 half steps, the tense tritone from last lesson, so this chord is called diminished. It is rare in pop songs. The other six are the everyday chords of the key of C.
Check yourself
Sara plays D, F and A together, all white keys. Which chord is it?
- F major, because F is in the middle
- D major, because white keys make major chords
- D minor, because D to F is 3 half steps
- D diminished, because it has no black keys
Show the answer
D minor, because D to F is 3 half steps
Right. D#, E, F is three half steps, a minor third, and D to A is seven. Root, +3, +7 is a minor triad.
Check yourself
Count from the root: major or minor triad?
- C E G
- A C E
- G B D
- E G B
- D F# A
- C Eb G
Show the answer
Major (root, +4, +7): C E G, G B D, D F# A
Minor (root, +3, +7): A C E, E G B, C Eb G
Check yourself
A song sheet shows these chord symbols. Match each to the notes you would play
Show the answer
- F → F A C
- Dm → D F A
- G → G B D
- Em → E G B
- Am → A C E
Lesson recap
- A triad stacks two thirds: root, third, fifth.
- Major triad = root, +4, +7 half steps. Minor triad = root, +3, +7. Only the third differs.
- A letter alone is a major chord (C); a small m means minor (Am).
- The C major scale contains three major chords (C, F, G), three minor (Dm, Em, Am) and one diminished (Bdim).
- A chord is its set of notes, in any order or octave.