Chord category
Seventh chords
The dominant seventh chord adds a fourth note to the major triad: the minor seventh. It creates tension and calls for resolution — the engine of almost all tonal music.
Theory
C7 is a major triad plus the minor seventh: the 1st, 3rd, 5th and flattened 7th.
Formula and steps
Degrees
1 – 3 – 5 – ♭7
Steps (semitones)
4 – 3 – 3
How they are used
It is the dominant chord: it sits on the V degree and resolves to the I. In blues and jazz it is used on any degree for its tense, expressive colour.
Progressions (roman numerals)
- V7 – I
- ii – V7 – I
- I7 – IV7 – V7 (blues)
Example sequences
- G7 – C
- Dm – G7 – C
- C7 – F7 – G7
Related chords
Alternative symbols
The dominant seventh is written simply C7. Do not confuse it with the major seventh (Cmaj7) or the minor seventh (Cm7). Its extensions are C9, C11 and C13.