Dominant seventh chord
The dominant seventh chord: a major triad with a minor seventh added. It sounds unsettled and pulls strongly toward a tonic a fourth above its root. Spelled in all twelve keys, with guitar shapes and piano diagrams.
On C
- Symbol
- C7
- Formula
- 1 3 5 ♭7
- Notes
- 4
- Also written
- Cdom7
What it sounds like
C7 is C, E, G and B♭: a major triad with a minor seventh added. The major third and the minor seventh form a tritone, E to B♭, which is traditionally regarded as the most unstable interval in tonal harmony. The tritone resolves when E rises to F and B♭ falls to A, which forms the third of the tonic. The minor seventh is a dissonance against the root, so the chord never sounds at rest. Its tension is strong and directional, and listeners hear it as a chord that must move on.
How it is used
The dominant seventh is built on the fifth degree in major keys, as V7, and in minor keys, where the harmonic minor raises the leading tone. It is the standard dominant in tonal music, and it resolves to the tonic in a V7 to I cadence. Dominant sevenths also appear as secondary dominants that tonicise other degrees. In the blues, I7, IV7 and V7 are the standard chords of the twelve-bar form. Jazz uses it in ii, V, I progressions, and rock and blues also use it on the flat seventh degree.
How it is built
The dominant seventh is a root with a major third, a perfect fifth and a minor seventh, 0, 4, 7 and 10 semitones above the root. Common symbols are C7, Cdom7 and C(dom7). The tritone between E and B♭ is spelled as an augmented fourth or a diminished fifth, depending on the inversion. The first inversion is C7/E, written 6/5 in figured bass, the second is C7/G, written 4/3, and the third is C7/B♭, written 4/2.
How to practise it
Play G7 and then C major, with the B moving up to C and the F falling to E. Repeat the same movement in F and B♭. Keep the hand in the same position so the voice leading is visible. Then play the dominant seventh in root position and in each inversion, and sing the bass note to hear the seventh resolve.
Dominant seventh chord in every key
Every chord is spelled by letter name. Click a symbol for its page, with inversions and guitar shapes.
| Chord | Notes | Hear it |
|---|---|---|
| C7 | C E G B♭ | |
| C♯7 | C♯ E♯ G♯ B | |
| D♭7 | D♭ F A♭ C♭ | |
| D7 | D F♯ A C | |
| E♭7 | E♭ G B♭ D♭ | |
| E7 | E G♯ B D | |
| F7 | F A C E♭ | |
| F♯7 | F♯ A♯ C♯ E | |
| G♭7 | G♭ B♭ D♭ F♭ | |
| G7 | G B D F | |
| G♯7 | G♯ B♯ D♯ F♯ | |
| A♭7 | A♭ C E♭ G♭ | |
| A7 | A C♯ E G | |
| B♭7 | B♭ D F A♭ | |
| B7 | B D♯ F♯ A |
Further reading
- Seventh Chords and How They Resolve in Tonal HarmonyHarmony · 7 min
- Chord Symbols Explained: Major, Minor, Seventh and Slash ChordsHarmony · 8 min
- The ii V I Progression in Major, Minor and Jazz StylesHarmony · 6 min
Questions
What is the difference between C7 and Cmaj7?
C7 is C, E, G and B♭. Cmaj7 is C, E, G and B. The seventh differs by one semitone, which separates a dominant from a tonic colour. C7 contains a tritone and pulls toward F, a fourth above. Cmaj7 has no tritone and sounds settled as a tonic.
How do you resolve a dominant seventh chord?
The tritone resolves: the third rises a semitone to the tonic note, and the seventh falls a step to the third of the tonic. In G7, B rises to C and F falls to E, which gives C major. The dominant seventh usually resolves to the tonic triad, and that resolution is what makes the chord sound like a dominant.
Why does a dominant seventh chord sound unfinished?
The minor seventh is a dissonance that has to move, and the tritone between the third and seventh is unstable. The chord points to a tonic a fourth above, and the ear expects that tonic. Until the resolution arrives, the chord sounds unfinished.