Seventh chords explained simply: take a three-note triad and stack one more third on top, and you get a four-note seventh chord. That extra note adds richness and emotion, which is why seventh chords power jazz, soul, R&B and lush pop. This guide covers the three you’ll use most — major 7 (maj7), minor 7 (min7) and dominant 7.
How seventh chords are built
A triad has a root, third and fifth. A seventh chord adds a fourth note a third above the fifth — the seventh. Starting from a C triad (C–E–G), the note a third above G is B (or B♭), so you get a Cmaj7 (C–E–G–B) or a C7 (C–E–G–B♭). Which seventh you add changes the chord’s flavor entirely. If thirds and sevenths are new, see music intervals explained.
The three main seventh chords
Major 7 (maj7)
A major triad plus a major seventh. Cmaj7 = C–E–G–B. It sounds smooth, warm and dreamy — think mellow jazz, soul and chill ballads. The interval between the root and seventh (C to B) is a major seventh, just a half step below the octave, which gives it that floating quality.
Minor 7 (min7)
A minor triad plus a minor seventh. Cm7 = C–E♭–G–B♭. It’s relaxed and mellow, less sad than a plain minor triad. Minor 7 chords are everywhere in funk, soul and neo-soul, often as the ii chord in a progression.
Dominant 7
A major triad plus a minor seventh. C7 = C–E–G–B♭. This is the bluesy, tense one. The dominant 7 contains a tritone (between E and B♭) that creates a strong pull to resolve. It’s the V chord in blues and jazz and the engine of the 12-bar blues. See the 12-bar blues progression for it in action.
| Chord | Formula | Notes (on C) | Feel |
|---|---|---|---|
| Cmaj7 | major triad + major 7th | C–E–G–B | warm, dreamy |
| Cm7 | minor triad + minor 7th | C–E♭–G–B♭ | mellow, smooth |
| C7 | major triad + minor 7th | C–E–G–B♭ | bluesy, tense |
Seventh chords in a key
Just like triads, you can build a seventh chord on each note of the scale. In C major the diatonic seventh chords are Cmaj7, Dm7, Em7, Fmaj7, G7, Am7 and Bm7♭5. Notice the V chord (G7) is the only dominant 7 — that’s why moving G7 to Cmaj7 feels so satisfying. This builds directly on your diatonic chords, and the ii–V–I in sevenths (Dm7–G7–Cmaj7) is the most important progression in jazz.
How to use them in songwriting
Try replacing plain triads with their seventh versions to add sophistication. Swap a basic G for G7 right before the home chord to strengthen the pull. Use maj7 and min7 chords to make a simple loop sound richer and more emotional. To dig deeper, explore extended chords like 9ths and 13ths, which stack even more thirds on top.
Frequently asked questions
What’s the difference between Cmaj7 and C7?
The seventh note. Cmaj7 has a major seventh (B), giving a smooth, dreamy sound, while C7 has a minor seventh (B♭), giving a tense, bluesy sound that wants to resolve. They share the same root triad but feel completely different.
Why is it called a “dominant” seventh?
Because it’s the seventh chord built on the fifth scale degree (the dominant). In C major, that’s G7. Its built-in tritone creates tension that resolves to the tonic, which is its main job in a progression.
Are seventh chords harder to play than triads?
Slightly, since they have four notes, but many seventh chords are easy fingerings on guitar and piano. Start with open dominant 7 shapes like G7 and E7, then add maj7 and min7 voicings as your hands get comfortable.
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