Chords
Seventh chord
A seventh chord is a four-note chord: a triad with a seventh added on top, such as Cmaj7 = C E G B or G7 = G B D F.
What is a seventh chord?
Take a triad (root, third, fifth) and stack one more third on top: that new note is the seventh. The chord now has four different notes. Its type depends on the starting triad and on the size of the seventh: major (11 semitones above the root), minor (10) or diminished (9).
Seventh chords are the basic vocabulary of jazz, soul and bossa nova, but also of the blues (A7, D7, E7) and plenty of pop songs.
What are the 5 types of seventh chords?
Here they are on C, each with a movable shape rooted on the 5th string, 3rd fret (from low E to high E, x = string not played):
| Type | Formula | Notes | Shape |
|---|---|---|---|
| Cmaj7 | 1 3 5 7 | C E G B | x3545x |
| C7 | 1 3 5 ♭7 | C E G B♭ | x3535x |
| Cm7 | 1 ♭3 5 ♭7 | C E♭ G B♭ | x3534x |
| Cm7♭5 | 1 ♭3 ♭5 ♭7 | C E♭ G♭ B♭ | x3434x |
| Cdim7 | 1 ♭3 ♭5 ♭♭7 | C E♭ G♭ A | x3424x |
Compare the shapes: from one row to the next, a single note moves by one fret. That is the clearest way to hear what each interval does.
The seventh chords in a key
Stack four notes of the C major scale on each degree and you get the four-note diatonic chords:
Cmaj7, Dm7, Em7, Fmaj7, G7, Am7, Bm7♭5 (Imaj7, ii7, iii7, IVmaj7, V7, vi7, viiø7).
The pattern is identical in every major key: maj7 on I and IV, m7 on ii, iii and vi, 7 on V, m7♭5 on vii. In G: Gmaj7, Am7, Bm7, Cmaj7, D7, Em7, F♯m7♭5.
Exercise: a ii-V-I in seventh chords
Play Dm7, G7, Cmaj7 without leaving frets 3 to 7:
- Dm7
x5756x(D A C F) - G7
3x343x(G F B D) - Cmaj7
x3545x(C G B E)
Watch the inner voices: the C in Dm7 falls to B in G7, then the F in G7 falls to E in Cmaj7. Four beats per chord, then two. If you're unsure about a shape, the chord identifier names the chord from the notes you place.
Common mistakes with seventh chords
- Mixing up 7 and maj7: "C7" has a minor seventh (B♭), "Cmaj7" a major seventh (B). They aren't variations of each other, they do completely different jobs.
- Dropping the wrong note: on four or five strings, leave out the fifth first. The third and the seventh define the chord.
- Turning every chord into a 7: G7 on the I chord of a song in G changes the colour (it suddenly sounds bluesy).
Key takeaways
- Seventh chord = triad + one more third, four notes.
- Five types: maj7, 7, m7, m7♭5, dim7.
- In major keys: Imaj7, ii7, iii7, IVmaj7, V7, vi7, viiø7.
- The third and seventh are essential, the fifth is optional.
Frequently asked questions
What does the 7 mean in a chord like G7?
A plain "7" means a minor seventh added to a major triad: G7 = G B D F. That is the dominant seventh chord. For a major seventh, the symbol is maj7 (Gmaj7 = G B D F♯).
What is the difference between Cmaj7 and C7?
One note: the seventh. Cmaj7 has B (major seventh), soft and stable, while C7 has B♭ (minor seventh), tense and pulling toward F. On guitar: x32000 for Cmaj7, x32310 for C7.
Which seventh chords should I learn first?
The open shapes E7 020100, A7 x02020, D7 xx0212, Am7 x02010, Em7 022030 and Cmaj7 x32000. Then move on to movable shapes on the 5th and 6th strings so you can play all five types in every key.
Related terms
- Dominant seventh chord
- Major seventh chord
- Minor seventh chord
- Half-diminished chord (m7♭5)
- Diatonic chords
Practise in the workshop
Take it from theory to the fretboard
Open the workshop tools and see this idea across the whole neck. Free account, no card needed.