Keys & Progressions
Why do so many songs use the same four chords?
They are not copying each other. They are drawing from one small family.
Take the guided lessonA key is a family of chords
Pick a scale, say C major, the white notes on a piano. Build a chord on each of its seven notes using only notes from that scale. You get seven chords, and that set is the key.
Those seven are guaranteed to fit with each other. Most songs never leave the family.
The family of C major
Six of the seven, all built from the same notes. Notice that some came out major and some came out minor.
Nobody decided which ones should be major or minor. It falls out of the scale on its own, and the pattern is identical in every key.
Numbers travel, letters do not
Because that pattern is the same everywhere, musicians number the chords instead of naming them. The 1, 4 and 5 are the major ones. The 6 is the wistful one.
That famous four chord progression is 1, 5, 6, 4. In C it is C, G, Am, F. In G it is G, D, Em, C. Different letters, same song.
Written in Roman numerals that is I, V, vi, IV. Capitals are major, lowercase are minor.
The four chords in motion
Play them in order, then loop back to the first one.
The pull back toward the 1 at the end is why this loop feels like it could run forever. The next lesson gives that pull a name.
The seven chords of any major key
The quality pattern never changes. Learn this one row of words and you know the chord family of all twelve keys.
| Number | Quality | In C | In G | What it tends to do |
|---|---|---|---|---|
| 1 | Major | C | G | Home. Everything resolves here |
| 2 | Minor | Dm | Am | Sets up the 5 chord |
| 3 | Minor | Em | Bm | Ambiguous, sits between 1 and 5 |
| 4 | Major | F | C | Away from home, but gently |
| 5 | Major | G | D | Tension. Pulls hard back to 1 |
| 6 | Minor | Am | Em | The wistful one. Shares notes with 1 |
| 7 | Diminished | Bdim | F#dim | Unstable. Rarely used on its own |
Major, minor, minor, major, major, minor, diminished. Say it out loud a few times. It is the single most reusable fact in this grade.
A song is in G major and uses the 1, 5, 6 and 4 chords. What is the 6 chord?
Order the qualities, from the 1 chord to the 7
The pattern that falls out of the major scale, in every key.
- 1the 1 chord goes here
- 2the 1 chord goes here
- 3the 1 chord goes here
- 4the 1 chord goes here
- 5the 1 chord goes here
- 6the 1 chord goes here
- 7the 1 chord goes here
Match each number to its chord in the key of C
Tap something on the left, then tap what it pairs with.
Which of these are true about the 1, 5, 6, 4 progression?
Takeaways
- A key is the seven chords you get from one scale.
- Their quality pattern is major, minor, minor, major, major, minor, diminished, in every key.
- Musicians number chords because numbers travel between keys and letters do not.
- 1, 5, 6, 4 is four chords out of that family. There is no magic in it.