We know that music has 12 distinct major keys, which means there are 12 different chord families. But here is the greatest secret of playing the guitar: you only need to memorize 5 main open-chord families.
By mastering the C, A, G, E, and D chord families (often called the CAGED system), you unlock the entire fretboard. You can play any song in any key just by shifting these five basic shapes using a capo or barre chords.
Every major chord family follows the exact same pattern. It always contains 3 Major chords, 3 minor chords, and 1 diminished chord. If you build a 3-note chord (a triad) from each note of the major scale, they fall into this unbreakable Roman Numeral order:
I (Major) | ii (minor) | iii (minor) | IV (Major) | V (Major) | vi (minor) | vii° (diminished)
Below is the complete breakdown of the 5 essential guitar chord families. The most important chords in each key (the I, IV, V, and vi) are marked in bold. These four chords are the foundation of 90% of popular music!
The "Distance" Rule: Major vs Minor
Have you ever wondered why some chords are Major and some are minor? It all comes down to the physical distance between the notes on your fretboard.
If you build a chord and the gap between the first note and the second note is 4 frets, it forms a bright, happy Major chord.
If the gap is only 3 frets, it forms a darker, sadder minor chord!
Because every major scale has a specific pattern of whole steps and half steps, the distances naturally fall into the exact same order every single time. That is why the I, IV, and V chords are ALWAYS Major, and the ii, iii, and vi chords are ALWAYS minor!
1. The C Major Family
The C Major scale has no sharps or flats (C-D-E-F-G-A-B).
| Scale Degree | Chord Quality | Notes |
|---|---|---|
| I (Root) | C Major | C - E - G |
| ii | D minor | D - F - A |
| iii | E minor | E - G - B |
| IV | F Major | F - A - C |
| V | G Major | G - B - D |
| vi (Rel. Minor) | A minor | A - C - E |
| vii° | B diminished | B - D - F |
2. The A Major Family
The A Major scale introduces three sharps (A-B-C#-D-E-F#-G#).
| Scale Degree | Chord Quality | Notes |
|---|---|---|
| I (Root) | A Major | A - C# - E |
| ii | B minor | B - D# - F# |
| iii | C# minor | C# - E - G# |
| IV | D Major | D - F# - A |
| V | E Major | E - G# - B |
| vi (Rel. Minor) | F# minor | F# - A - C# |
| vii° | G# diminished | G# - B - D |
3. The G Major Family
The G Major scale has just one sharp (G-A-B-C-D-E-F#).
| Scale Degree | Chord Quality | Notes |
|---|---|---|
| I (Root) | G Major | G - B - D |
| ii | A minor | A - C - E |
| iii | B minor | B - D# - F# |
| IV | C Major | C - E - G |
| V | D Major | D - F# - A |
| vi (Rel. Minor) | E minor | E - G - B |
| vii° | F# diminished | F# - A - C |
4. The E Major Family
The E Major scale has four sharps (E-F#-G#-A-B-C#-D#).
| Scale Degree | Chord Quality | Notes |
|---|---|---|
| I (Root) | E Major | E - G# - B |
| ii | F# minor | F# - A - C# |
| iii | G# minor | G# - B - D# |
| IV | A Major | A - C# - E |
| V | B Major | B - D# - F# |
| vi (Rel. Minor) | C# minor | C# - E - G# |
| vii° | D# diminished | D# - F# - A |
5. The D Major Family
The D Major scale has two sharps (D-E-F#-G-A-B-C#).
| Scale Degree | Chord Quality | Notes |
|---|---|---|
| I (Root) | D Major | D - F# - A |
| ii | E minor | E - G - B |
| iii | F# minor | F# - A - C# |
| IV | G Major | G - B - D |
| V | A Major | A - C# - E |
| vi (Rel. Minor) | B minor | B - D# - F# |
| vii° | C# diminished | C# - E - G |
How to Use This Information
Next time you want to write a song, pick one of these 5 families. Choose the I chord to start, mix in the IV, V, and vi chords, and you are guaranteed to write a progression that sounds mathematically and musically perfect!
Learning how these chord families relate to each other will significantly improve your ability to play guitar by ear and understand what makes your favorite songs sound so good.