A seventh chord is the combination of a triad and an interval of a seventh.
Five types of seventh chords are commonly used.
A major triad and a minor seventh combine to form a dominant seventh chord.
Dominant seventh chords are abbreviated with a simple 7.
Let's examine a C dominant seventh chord.
C – E – G is the major triad.
C – Bb is the minor seventh.
When combined, they form a C dominant seventh chord: C – E – G – Bb.
Next, let's examine an F# dominant seventh chord.
F# – A# – C# is the major triad.
F# – E is the minor seventh.
When combined, they form an F# dominant seventh chord: F# – A# – C# – E.
Next, let's examine an Ab dominant seventh chord.
Ab – C – Eb is the major triad.
Ab – Gb is the minor seventh.
When combined, they form an Ab dominant seventh chord: Ab – C – Eb – Gb.
A major triad and a major seventh combine to form a major seventh chord.
Major seventh chords are abbreviated with a capital 'M' and a 7.
Let's examine a C major seventh chord.
C – E – G is the major triad.
C – B is the major seventh.
When combined, they form a C major seventh chord: C – E – G – B.
Next, let's examine an F# major seventh chord.
F# – A# – C# is the major triad.
F# – E# is the major seventh.
When combined, they form an F# major seventh chord: F# – A# – C# – E#.
Next, let's examine an Ab major seventh chord.
Ab – C – Eb is the major triad.
Ab – G is the major seventh.
When combined, they form an Ab major seventh chord: Ab – C – Eb – G.
A minor triad and a minor seventh combine to form a minor seventh chord (m7).
Minor seventh chords are abbreviated with a lower-case 'm' and a 7.
Let's examine a C minor seventh chord.
C – Eb – G is the minor triad.
C – Bb is the minor seventh.
When combined, they form a C minor seventh chord: C – Eb – G – Bb.
Next, let's examine an F# minor seventh chord.
F# – A – C# is the minor triad.
F# – E is the minor seventh.
When combined, they form an F# minor seventh chord: F# – A – C# – E.
Next, let's examine an Ab minor seventh chord.
Ab – Cb – Eb is the minor triad.
Ab – Gb is the minor seventh.
When combined, they form an Ab minor seventh chord: Ab – Cb – Eb – Gb.
A diminished triad and a minor seventh combine to form a half-diminished seventh chord.
Half-diminished seventh chords are abbreviated with a slashed circle and a 7.
Let's examine a C half-diminished seventh chord.
C – Eb – Gb is the diminished triad.
C – Bb is the minor seventh.
When combined, they form a C half-diminished seventh chord: C – Eb – Gb – Bb.
Next, let's examine an F# half-diminished seventh chord.
F# – A – C is the diminished triad.
F# – E is the minor seventh.
When combined, they form an F# half-diminished seventh chord: F# – A – C – E.
Next, let's examine an Ab half-diminished seventh chord.
Ab – Cb – Ebb is the diminished triad.
Ab – Gb is the minor seventh.
When combined, they form an Ab half-diminished seventh chord: Ab – Cb – Ebb – Gb.
Finally, a diminished triad and a diminished seventh combine to form a diminished seventh chord (or fully-diminished seventh chord).
Diminished seventh chords are abbreviated with an open circle and a 7.
Let's examine a C diminished seventh chord.
C – Eb – Gb is the diminished triad.
C – Bbb is the diminished seventh.
When combined, they form a C diminished seventh chord: C – Eb – Gb – Bbb.
Next, let's examine an F# diminished seventh chord.
F# – A – C is the diminished triad.
F# – Eb is the diminished seventh.
When combined, they form an F# diminished seventh chord: F# – A – C – Eb.
Next, let's examine an Ab diminished seventh chord.
Ab – Cb – Ebb is the diminished triad.
Ab – Gbb is the diminished seventh.
When combined, they form an Ab diminished seventh chord: Ab – Cb – Ebb – Gbb.
Use this chart to reference the five common types of seventh chords.