Seventh Chords
Put one more third on top of a triad and the chord stops being a plain statement. Depending on which seventh you add, it either floats or starts pulling toward the next chord.
- 4 notes
- 1 3 5 7
- six kinds
which styles use it
- Jazz
- Soul & R&B
- Deep house
- Bossa nova
In short
A seventh chord is a triad with a fourth note stacked a third above the fifth. Which triad you start from and which seventh you add gives six chords that turn up constantly. The major seventh sits one half step under the root and makes the chord float; the minor seventh sits a whole step under and either relaxes the chord or makes it pull, depending on the triad underneath.
A triad tells you where you are. A seventh chord tells you where you are going, or that you are staying put on purpose.
How to build it
- Take a triad and add one more third
Two thirds make a triad, three thirds make a seventh chord. On a keyboard it is every other white key if you start on C and stay in the key.
- Check which seventh you landed on
Eleven half steps above the root is a major seventh and ten is a minor seventh. That one key is the difference between a chord that rests and a chord that moves.
- Let the triad decide the rest
Major triad with a major seventh gives maj7. Major with a minor seventh gives the dominant. Minor with a minor seventh gives m7. The rest are variations on those three.
Where you run into this
- In jazz, where the seventh chord is the default and a plain triad is the exception.
- In soul, house and neo-soul, where m7 and maj7 do most of the work.
- In blues and rock, where the dominant seventh appears on chords that in theory should not have one.
The six side by side
Same root, one note at a time:
- Cmaj7, floating
- C7, pulling toward F
- Cm7, soft and settled
- Cm7b5, leaning toward a dominant
- Cdim7, able to go anywhere
- CmMaj7, uneasy and on its way down