A 9 chord without a 7 is known as an add9 chord, or added ninth chord. This specific type of chord incorporates a ninth interval above its root without necessarily including the seventh, which differentiates it from a standard ninth chord.
Understanding the Add9 Chord
Unlike traditional ninth chords that build upon a dominant seventh chord structure (root, third, fifth, seventh, ninth), an add9 chord is formed by adding a ninth to a basic triad (root, third, fifth). This omission of the seventh interval results in a chord with a less dissonant or unresolved sound, often described as more open, lush, or suspended.
Construction and Examples
The construction of an add9 chord depends on the quality of its underlying triad (major, minor, or diminished) and the interval of the added ninth (typically a major ninth, but can be minor in some contexts).
Here are common examples illustrating the structure of add9 chords:
- Cadd9: This chord consists of the notes C (root), E (major third), G (perfect fifth), and D (major ninth). It provides a bright, full sound.
- Cmadd9: This chord includes C (root), E flat (minor third), G (perfect fifth), and D (major ninth). It offers a melancholic yet rich quality.
- Cdimadd9: This chord comprises C (root), E flat (minor third), G flat (diminished fifth), and D (major ninth). This less common variation has a more tense, distinctive sound.
Chord Components at a Glance
To further clarify, here's a breakdown of notes for common add9 chords with C as the root:
| Chord Type | Root | Third | Fifth | Ninth | Characteristics |
|---|---|---|---|---|---|
| Cadd9 | C | E | G | D | Major triad with an added major ninth. |
| Cmadd9 | C | Eb | G | D | Minor triad with an added major ninth. |
| Cdimadd9 | C | Eb | Gb | D | Diminished triad with an added major ninth. |
Distinguishing from Ninth Chords
The key difference lies in the presence or absence of the seventh. A standard ninth chord (e.g., C9, Cmaj9, Cm9) includes the seventh, which often creates a sense of tension or directionality, particularly in dominant ninth chords that lead to resolution. Add9 chords, by omitting the seventh, avoid this tension, making them versatile for creating atmospheric or consonant harmonies in various musical genres. They are frequently employed in contemporary music to add color without the functional implications of a seventh chord.
