Chords in Every Key: Complete Diatonic Guide

Diatonic chords are the seven chords built from the seven notes of a major or minor scale. In C Major (C–D–E–F–G–A–B), each scale degree gets its own chord:

• C Major (I)
• D minor (ii)
• E minor (iii)
• F Major (IV)
• G Major (V)
• A minor (vi)
• B diminished (vii°)

These seven chords form the backbone of most pop, rock, folk, and classical music. Knowing them means you can write or transpose a song without guesswork.

How to Build Diatonic Chords

To build diatonic chords, stack every other note of the scale starting from each scale degree:

• Start on C: C–E–G = C Major (C, E, G are scale degrees 1, 3, 5)
• Start on D: D–F–A = D minor (D, F, A are scale degrees 2, 4, 6; F is lowered because it’s not in C Major—wait, it is. D–F–A is the ii chord built on D using only C Major notes)

Actually, let me clarify: D–F–A in C Major. D is the starting note (scale degree 2), skip E, land on F (scale degree 4), skip G, land on A (scale degree 6). So D–F–A. F is natural (part of the C Major scale), A is natural. That’s a minor triad: root, minor third, perfect fifth. D–F–A = D minor.

Every diatonic chord in a key uses only the notes of that key’s scale. No accidentals, no borrowed chords.

Diatonic Chords in Major Keys

C Major (most common starting point)

I: 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: A minor (A–C–E)
vii°: B diminished (B–D–F)

This set appears in countless songs. “I–IV–V–I” is a foundational progression. “vi–IV–I–V” (A minor–F Major–C Major–G Major) is a modern pop standby.

G Major

I: G Major
ii: A minor
iii: B minor
IV: C Major
V: D Major
vi: E minor
vii°: F# diminished

Transpose a C Major progression to G? Just shift each chord up a fifth (C→G, F→C, G→D, etc.).

D Major, A Major, E Major, F Major

Each major key follows the same pattern: I and IV and V are major, ii, iii, and vi are minor, vii is diminished. The only difference is which notes are sharp or flat.

Use our music key chart to see all 12 major keys at once. Bookmark it. You’ll reference it constantly.

Diatonic Chords in Minor Keys (Natural Minor)

A minor key borrows its notes from a relative major. A minor is the relative minor of C Major (same notes: A–B–C–D–E–F–G). So:

i: A minor (A–C–E)
ii°: B diminished (B–D–F)
III: C Major (C–E–G)
iv: D minor (D–F–A)
v: E minor (E–G–B)
VI: F Major (F–A–C)
VII: G Major (G–B–D)

Notice the Roman numerals. Lowercase (i, ii, iv, v) means minor or diminished. Uppercase (III, VI, VII) means major. This is the music theory convention.

Natural minor sounds melancholic. But many songs use harmonic minor (raising the seventh note) or melodic minor (raising sixth and seventh in ascending, lowering in descending), which create different diatonic sets. For now, stick with natural minor.

Understanding Chord Function

Beyond memorizing chords, understand why they work:

The tonic (I, i) feels like home. Chord progressions resolve to it.
The dominant (V) feels unresolved, pulling back to I. V–I is the strongest cadence in music.
The subdominant (IV) sits between I and V, adding sophistication.
The relative minor (vi in major, III in minor) sounds introspective but still part of the key.

A song that alternates vi–IV–I–V explores introspection, hope, and resolution—all through chord choice alone.

Using Diatonic Chords in Songwriting

Start with a chord progression using only diatonic chords from one key. Maybe I–V–vi–IV in C Major: C–G–Am–F. Play it. If it works, you’re done. Most hit songs use only diatonic chords.

Want more tension? Add a secondary dominant. Play V/vi (E Major, which contains E–G#–B). That G# isn’t in C Major, so it creates surprise, then resolves smoothly back to A minor. These borrowed chords are outside the diatonic set but still sound natural.

Learn how to transpose progressions to different keys so you can move your song up or down to match a vocalist’s range. Once you know diatonic chords, transposition is just shifting every chord by the same interval.

Major vs. Relative Minor: Same Chords, Different Feel

C Major and A minor share identical diatonic chords. But a song built on C–G–Am–F feels different depending on which chord you emphasize as “home”:

Emphasize C: I–V–vi–IV sounds uplifting, resolved.
Emphasize A minor: vi–iii–i–iv sounds introverted, searching.

Understand relative major and minor to unlock this relationship. It’s foundational to music composition.

Frequently Asked Questions

Why is the vii chord always diminished?

The vii chord (built on the seventh scale degree) contains the tritone—the interval between scale degrees 7 and 3 (e.g., B and F in C Major). The tritone is inherently unstable and sounds unsettling. That’s why VII resolves strongly back to I. Diminished chords are rarely used except as passing chords or with modification.

Can I use non-diatonic chords in my song?

Yes. Borrowed chords (pulling from the parallel major or minor) and secondary dominants add color. But anchor your song in diatonic harmony first. Diatonic progressions teach ear training and taste.

Are there only seven possible chords in a key?

There are seven diatonic triads (three-note chords). Add sevenths and extensions, and you get more. C Major 7, D minor 7, E minor 7, etc. But the foundational seven triads are your core palette.

How do I remember all 12 keys’ diatonic chords?

Use the circle of fifths. Each key sits a fifth apart from the next. Learn one key deeply (C Major is traditional). Then learn that C Major is the I chord of C, the IV of G, and the V of F. Relationships anchor memory better than rote memorization.