Chords and Common Progressions

A chord is three or more notes played together. Most of popular music is built from a handful of chord shapes arranged into short, repeating progressions.

Triads

The basic chord is a triad: a root, a third and a fifth. In semitones above the root:

Chord	Shape	From C	Sound
Major	0-4-7	C E G	Bright, stable
Minor	0-3-7	C E♭ G	Dark, stable
Diminished	0-3-6	C E♭ G♭	Tense, unstable
Augmented	0-4-8	C E G♯	Eerie, unresolved
Sus2	0-2-7	C D G	Open, ambiguous
Sus4	0-5-7	C F G	Suspended, wants to resolve

Seventh chords

Add a fourth note, the 7th, for richer harmony — essential in house, R&B, lo-fi and jazz:

Chord	Shape	From C
Major 7 (maj7)	0-4-7-11	C E G B
Minor 7 (m7)	0-3-7-10	C E♭ G B♭
Dominant 7 (7)	0-4-7-10	C E G B♭
Half-diminished (m7♭5)	0-3-6-10	C E♭ G♭ B♭

Stack another third and you get 9ths (add 14 semitones above the root) — a minor 9 is the lush chord behind a lot of deep house and neo-soul.

The chords of a key

Build a triad on each note of a scale using only that scale's notes and you get the key's diatonic chords. Roman numerals name them by scale degree — uppercase for major, lowercase for minor, ° for diminished — so a progression can be described in any key at once.

Major key (C major):

I	ii	iii	IV	V	vi	vii°
C	Dm	Em	F	G	Am	B°

Minor key (A minor):

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

Same notes, different home — which is why the numerals shift.

Progressions that keep coming back

Progression	In C major / A minor	Feel	Heard in
I–V–vi–IV	C–G–Am–F	Uplifting, anthemic	Countless pop songs
vi–IV–I–V	Am–F–C–G	Same chords, more wistful	Pop, EDM
I–vi–IV–V	C–Am–F–G	Classic, nostalgic	50s doo-wop, ballads
ii–V–I	Dm7–G7–Cmaj7	Resolving, jazzy	Jazz, R&B, lo-fi
i–VI–III–VII	Am–F–C–G	Epic, driving	EDM, trance, rock
i–iv–v	Am–Dm–Em	Dark, folk	Minor ballads
i–VII–VI–VII	Am–G–F–G	Rocking, open	Rock, house
i–iv (two chords)	Am–Dm	Hypnotic	House, techno, hip-hop

Notice I–V–vi–IV and i–VI–III–VII use the same four chords in a different order. Where the cycle starts decides whether it reads as major or minor.

Voicing: making chords sound produced

The same chord can be arranged many ways. Block triads in root position sound stiff; good voicing is mostly about moving as little as possible.

1. Inversions. Put a different note at the bottom: C E G (root), E G C (first inversion), G C E (second). Choose the inversion that keeps each chord close to the last.
2. Voice leading. Moving C–G–Am–F with inversions, most notes move by one or two semitones or stay put. The progression sounds smooth instead of jumping.
3. Spread the voicing. Drop the root an octave below the rest, or put the 3rd on top. Keep notes at least a 5th apart below about C3 to avoid mud.
4. Let the bass take the root. If a bass part plays roots, the chord part can skip the root and play only the colour notes (3rd, 7th, 9th) — the standard lush-keys sound.

Borrowed chords

Taking one chord from the parallel key adds instant colour. In C major, borrowing from C minor gives iv (Fm), ♭VI (A♭) and ♭VII (B♭). Try C–F–Fm–C: the minor iv is the bittersweet move in countless ballads.

Rhythm of the changes

How often chords change matters as much as which chords: one chord per bar is the norm in pop and dance music, two per bar feels busier, and one per two bars gives room for a melody. Changing chord just before the bar line (anticipating by an eighth or sixteenth) adds push.