Building Chords from Scales
One of the most powerful concepts in music theory is that chords are built from scales. By stacking every other note of a scale (1st, 3rd, 5th), you create a triad on each scale degree.
Chords of the Major Scale
When you build triads on each degree of a major scale, you always get the same pattern of chord qualities:
| Degree | Roman Numeral | Quality | In C Major |
|---|---|---|---|
| I | I | Major | C (C–E–G) |
| II | ii | Minor | Dm (D–F–A) |
| III | iii | Minor | Em (E–G–B) |
| IV | IV | Major | F (F–A–C) |
| V | V | Major | G (G–B–D) |
| VI | vi | Minor | Am (A–C–E) |
| VII | vii° | Diminished | Bdim (B–D–F) |
This pattern is the same in every major key. Once you know it, you can instantly find all the chords that naturally belong to any key. For example, in G major the chords are: G – Am – Bm – C – D – Em – F♯dim.
Common Chord Progressions
Certain combinations of these chords appear over and over in popular music. Here are some of the most common progressions:
I – V – vi – IV
In C: C – G – Am – F
One of the most popular progressions in modern pop music. Uplifting and emotional.
I – IV – V – I
In C: C – F – G – C
A classic and resolved progression. The foundation of rock, blues, and country.
ii – V – I
In C: Dm – G – C
The signature jazz progression. Smooth resolution through the circle of fifths.
vi – IV – I – V
In C: Am – F – C – G
A minor-starting variation of the pop progression. Bittersweet and anthemic.
Practice Tips
C major has no sharps or flats, making it the easiest key to learn chords and scales. Master the C major scale and its seven triads before moving to other keys.
Practice all seven chords that belong to a single key as a group. Play I–ii–iii–IV–V–vi–vii°–I up and back down. This trains your ear to hear how chords relate within a key.
Play a major chord, then lower just the third by one semitone to make it minor. Listen carefully to how the mood shifts. Do this with every root note to internalize the difference.
Pick a key and choose 3–4 chords from its chord family. Experiment with different orders. You'll be surprised how many songs you can write using just four chords from the same key.