Dominant Seventh Chords (7)
Dominant seventh chords create strong tension that wants to resolve, making them the backbone of functional harmony. They have a bluesy, driving quality that's essential in jazz, blues, and rock.
It's a Major 7 with the 7th 1 semitone lower, or a Minor 7 with the 3rd 1 semitone higher.
Structure
A dominant seventh chord consists of:
- Root - The fundamental note that gives the chord its name
- Major Third - 4 semitones above the root
- Perfect Fifth - 7 semitones above the root
- Minor Seventh - 10 semitones above the root
Examples:
- C7: C - E - G - Bb
- D7: D - F# - A - C
- E7: E - G# - B - D
- F7: F - A - C - Eb
See that it is a major + dim combination.
- C (Root)
- E (Major Third - 4 semitones from C)
- G (Perfect Fifth - 7 semitones from C)
- B♭ (Minor Seventh - 10 semitones from C)
As a Transition
Dominant 7 chords are often used for 5-1 movements as the V7 dominant chord or other substitutions which we will learn later. Here it is used as a 5-1 resolution from C7 to F in a classical manner, and C7 to FM7 in a more modern way.
Sound Characteristics
- Mood: Driving, tense, bluesy
- Symbol: C7, Cdom7
Dominant seventh chords are the most important seventh chords in traditional harmony. The tritone interval between the 3rd and 7th creates strong tension that naturally resolves to the tonic, making them essential for establishing key centers and creating forward motion in music.