Chord category
Added-note chords
An added chord adds a note to the triad without stacking the seventh: the most common is the added ninth (add9). It brings richness without the tension of an extended chord.
Theory
Cadd9 is a major triad plus the ninth, but without the seventh. The added sixth gives C6, and both together give C6/9.
Formula and steps
Degrees
1 – 3 – 5 – 9
Steps (semitones)
4 – 3 – 7
How they are used
Very common in pop, folk and rock for their open, luminous sound. The add9 is a bright replacement for the plain triad.
Progressions (roman numerals)
- Iadd9 – IV – V
- I – V – vi(add9) – IV
Example sequences
- Cadd9 – F – G
- C – G – Am – Fadd9