A seventh chord takes a triad and adds one more note - a seventh interval above the root. Four notes instead of three.
If a triad is a simple three-ingredient dish, a seventh chord adds a fourth ingredient that gives it more depth. Richer, more complex, more interesting.
How seventh chords are built
Start with any triad, then stack another third on top. The type of triad and the type of seventh create different combinations.
The five main types
Each type has a distinct character. Tap to hear them.
Major 7th (maj7)
Major triad + major 7th. Smooth, dreamy, warm. Common in jazz and neo-soul.
Minor 7th (min7)
Minor triad + minor 7th. Mellow, slightly melancholic. Everywhere in R&B and lo-fi.
Dominant 7th (7)
Major triad + minor 7th. Tense, wants to resolve. The engine of blues and funk.
Diminished 7th (dim7)
Diminished triad + diminished 7th. Dark, dramatic, unstable. Used sparingly for tension.
Half-diminished 7th (m7b5)
Diminished triad + minor 7th. Tense but less extreme than full dim7. The naturally occurring vii chord in major keys. Common in jazz and bossa nova.
Major 7 vs Dominant 7
These two are easy to mix up. Both start with a major triad - the only difference is whether the seventh is major or minor.
Major 7th (B) versus minor 7th (Bb).
Why seventh chords matter
Triads sound complete but simple. Seventh chords add colour and movement. They're what separate a basic progression from one that sounds rich and professional.
Key takeaway
Seventh chords = triad + a 7th. Five main types: maj7 (dreamy), min7 (mellow), dominant 7 (tense), dim7 (dramatic), m7b5 (jazz tension). The fourth ingredient adds depth.
Next: going even further with 9ths, 11ths, and 13ths - extended chords.
Generate seventh chord progressions
Starts supports maj7, min7, dom7, and more chord types in MIDI export.