Chords in a Key

How to find the chords in a key

Start on each note of the major scale and stack two more notes, skipping one each time, using only the scale’s notes. In C major:

Numeral	I	ii	iii	IV	V	vi	vii°
Notes	C E G	D F A	E G B	F A C	G B D	A C E	B D F
Chord	C	Dm	Em	F	G	Am	B°
Quality	major	minor	minor	major	major	minor	diminished

Because every major scale has the same pattern of steps, every major key has the same pattern of chords: major, minor, minor, major, major, minor, diminished. Learn it once and it works in all twelve keys.

What the Roman numerals mean

The numeral is the scale degree the chord is built on, and its case tells you the chord type:

Mark	Meaning	Example in C
I, IV, V	Capital: major	C, F, G
ii, iii, vi	Small: minor	Dm, Em, Am
°	Diminished	vii° = B°
+	Augmented	—
7	Adds the 7th	V7 = G7

Numerals describe a chord’s job rather than its name, so a progression written in numerals works in any key. ii–V–I is Dm–G–C in C major and Am–D–G in G major.

Chords in every major key

All twelve major keys, in circle of fifths order. F♯ major sounds the same as G♭ major, and D♭ major the same as C♯ major: they are spelled differently but played on the same keys.

Key	I	ii	iii	IV	V	vi	vii°
C major	C	Dm	Em	F	G	Am	B°
G major	G	Am	Bm	C	D	Em	F♯°
D major	D	Em	F♯m	G	A	Bm	C♯°
A major	A	Bm	C♯m	D	E	F♯m	G♯°
E major	E	F♯m	G♯m	A	B	C♯m	D♯°
B major	B	C♯m	D♯m	E	F♯	G♯m	A♯°
F♯ major	F♯	G♯m	A♯m	B	C♯	D♯m	E♯°
D♭ major	D♭	E♭m	Fm	G♭	A♭	B♭m	C°
A♭ major	A♭	B♭m	Cm	D♭	E♭	Fm	G°
E♭ major	E♭	Fm	Gm	A♭	B♭	Cm	D°
B♭ major	B♭	Cm	Dm	E♭	F	Gm	A°
F major	F	Gm	Am	B♭	C	Dm	E°

The key signature supplies the sharps and flats, so every chord in the key uses only notes from that key’s scale.

The primary chords: I, IV and V

I, IV and V are the three major chords in a major key, and between them they contain every note of the scale. That’s why so many songs, from folk and country to rock and roll, need nothing else. On the circle of fifths they’re neighbors: F, C and G sit side by side.

Chords in a minor key

In a natural minor key the pattern starts from the minor chord. In A minor:

Numeral	i	ii°	III	iv	v	VI	VII
Chord	Am	B°	C	Dm	Em	F	G

These are the same seven chords as C major, the relative major, starting from a different home. In practice, minor-key music often raises the 7th note (the harmonic minor), which turns v into a major V (E in A minor) for a stronger pull back home.

The free minor key chord chart lists these chords, with V and vii°, in all 12 minor keys.

What each chord does

Function	Chords	Feel
Tonic	I, vi, iii	Home, at rest
Predominant	IV, ii	Moving away
Dominant	V, vii°	Tension that pulls back to I

Most progressions travel tonic → predominant → dominant → tonic. (iii is sometimes counted as a dominant chord instead.)

Common chord progressions

Progression	In C major	Heard in
I–IV–V	C–F–G	Rock, folk, country
I–V–vi–IV	C–G–Am–F	Pop anthems
vi–IV–I–V	Am–F–C–G	The same chords, starting on minor
I–vi–IV–V	C–Am–F–G	1950s doo-wop
ii–V–I	Dm7–G7–Cmaj7	Jazz’s most common move

Many bands write these as numbers instead (1–4–5, 1–5–6m–4), so one chart works in any key: see the Nashville number system. To hear a progression’s chords and see them on piano, guitar and ukulele, look each one up in the chord finder.

The 12-bar blues uses only I, IV and V, as 7th chords, over twelve measures:

I7	I7	I7	I7
IV7	IV7	I7	I7
V7	IV7	I7	V7

The last measure’s V7 leads back to the top; on the final time round, end on I7 instead.

Cadences: how phrases end

A cadence is the chord move at the end of a phrase, like punctuation.

Cadence	Chords	In C	Feel
Authentic	V–I	G–C	Full stop
Plagal	IV–I	F–C	The “Amen” ending
Half	I–V (or any chord to V)	C–G	Comma, unfinished
Deceptive	V–vi	G–Am	Surprise

British books use different names for some of these (perfect, imperfect, interrupted); see American vs British music terms.

Learn it step by step

Trebly’s chords in a key lesson has you number every chord in C major, find I, IV and V in G and F major, and choose the chords for Twinkle, Twinkle, then hear the tune played with them. Major and Minor Chords comes first.