The word “seventh” does not mean the chord has seven notes. It means the chord includes a note that is some type of seventh above the root.
Seventh chords are common in blues, jazz, funk, soul, pop and many other styles. Beginners often meet dominant seventh shapes first, such as E7, A7 and D7.
A seventh chord begins with a triad and adds a note a seventh above the root. Different kinds of seventh create different amounts of warmth, tension and expectation.
Dominant seventh
A chord such as G7 contains a major triad plus a minor seventh. It has strong tension and often wants to resolve to C.
Why guitar shapes omit notes
A theoretical chord may contain four or more different notes, but a practical guitar voicing may repeat or omit a less important note so the shape remains playable.
Major 7 and dominant 7 are not the same
Cmaj7 contains C, E, G and B and has a smooth, spacious colour. C7 contains C, E, G and B-flat and has a stronger pull toward F. The one-semitone difference between B and B-flat changes the chord function considerably.
Minor 7 combines a minor triad with a minor seventh
Cm7 contains C, E-flat, G and B-flat. It is common in soul, funk, blues and jazz, and often sounds softer and less final than a plain minor triad.
Work through the shape
- Learn E7, A7 and D7 as variations of familiar open chords.
- Move between a major chord and its dominant seventh version.
- Listen for increased tension.
- Try a simple blues progression using only seventh chords.
- Compare C major, Cmaj7 and C7 while listening to the top note.
- Play E minor and Em7, then notice how adding the open D changes the colour without changing the root.
When notes buzz or disappear
All seventh chords are treated as blues chords
The word seventh describes an added interval, but the chord quality matters. Major 7, dominant 7, minor 7 and diminished 7 have different structures and musical roles.
You count strings instead of intervals
The number seven refers to the interval from the root, not the number of strings or fingers used.