Seventh chords

What is a seventh chord?

A triad is three notes — root, third, fifth. A seventh chord takes that triad and adds one more note on top: the seventh degree of the scale above the root.

That fourth note changes the character of the chord dramatically. Triads feel stable and complete. Seventh chords feel richer, more coloured — and often more restless. They want to go somewhere.

There are four main types, each with a different combination of triad and seventh.

Major 7th (maj7)

A major triad with a major seventh on top. The seventh is 11 semitones above the root — just one semitone below the octave. It barely misses completing the octave, which gives it a floaty, unresolved quality.

Formula: 1 – 3 – 5 – 7

Another way to hear it: a major 7th chord is two triads stacked on top of each other. Cmaj7 = C major + E minor. The E minor triad (E – G – B) sits on top of the C major triad (C – E – G), sharing the E and G.

Cmaj7 in C major is C – E – G – B. Click each note to hear it:

It sounds warm, lush, sophisticated — you hear it everywhere in soul, R&B, and jazz. On guitar, Cmaj7 is one of the first chords worth learning beyond the open basics:

Dominant 7th (7)

A major triad with a minor seventh — one semitone lower than the major 7th. It sounds tense, bluesy, like something is unfinished. That tension has a name: the tritone, the interval between the major 3rd and the minor 7th inside the chord.

Formula: 1 – 3 – 5 – ♭7

In terms of triads: G7 = G major + B diminished. The B diminished triad (B – D – F) sits on top of G major (G – B – D). That B diminished triad is where the tension lives — diminished chords are inherently unstable, and here it’s sitting right inside your dominant chord.

G7 is G – B – D – F. The B and the F form the tritone — they pull against each other, creating a strong urge to resolve back to C. Click each note:

This is the most important seventh chord in music. Every blues, every jazz standard, most rock. When guitarists talk about a “7 chord” — an E7, A7, D7 — this is what they mean. Open G7 on guitar:

Minor 7th (m7)

A minor triad with a minor seventh. Where the dominant 7th is tense and yearning, the minor 7th is mellow and smooth — it has tension, but it wears it comfortably.

Formula: 1 – ♭3 – 5 – ♭7

In terms of triads: Am7 = A minor + C major. The C major triad (C – E – G) sits on top of A minor (A – C – E). Notice this is the mirror image of Cmaj7 — Cmaj7 is C major + E minor, Am7 is A minor + C major. They share three of their four notes.

Am7 is A – C – E – G. Compared to plain Am, the added G takes the edge off — it sounds less bleak, more laid back.

Minor 7ths are everywhere in funk, soul, and neo-soul. The opening riff of “Superstition” by Stevie Wonder is essentially E♭m7 on repeat.

Half-diminished (m7♭5)

A diminished triad — root, flat third, flat fifth — with a minor seventh on top. The flat fifth makes it unstable; the minor seventh stops it from being as stark as a full diminished chord. Dark and uneasy, but not quite as dramatic.

Formula: 1 – ♭3 – ♭5 – ♭7

In terms of triads: Bm7♭5 = B diminished + D minor. The D minor triad (D – F – A) sits on top of B diminished (B – D – F). Both triads are dark in character, which is why this chord sounds particularly uneasy.

Also written with the symbol ø. In C major it appears naturally on the 7th degree: B – D – F – A.

Common in jazz, particularly as the ii chord in minor key progressions: Bm7♭5 → E7 → Am.

The major scale in seventh chords

Build a seventh chord on every degree of the major scale and you get the same seven chords every time, in the same pattern. Change the key and the names change — but the pattern doesn't.

The pattern is always: maj7 – m7 – m7 – maj7 – 7 – m7 – m7♭5.

The V chord is the only dominant 7th. That tritone inside it is what makes the V → I movement the most satisfying progression in Western music. Nearly every song you know uses it somewhere.