Seventh chords and extensions
Add another third on top of a triad and you get a seventh chord.
| Symbol | Name | On C |
|---|---|---|
| Cmaj7 | major seventh | C E G B |
| C7 | dominant seventh | C E G B♭ |
| Cm7 | minor seventh | C E♭ G B♭ |
| Cm7♭5 | half-diminished | C E♭ G♭ B♭ |
| C°7 | fully diminished | C E♭ G♭ B𝄫 |
The dominant seventh is the chord built on the 5th degree (G7 in C major). It pulls strongly towards the tonic.
Extensions and suspensions
- 9 adds a ninth (D over C) on top of the seventh chord: C9 = C E G B♭ D.
- add9 adds the ninth without the seventh.
- sus4 replaces the third with the fourth.
Inversions
The lowest note can be any chord note. Third in the bass is first inversion, fifth second inversion, seventh third inversion.