Aadd9 — A added ninth chord
A major triad with the ninth added and no seventh, so the triad is unaltered.
- 1 = A
- 9 = B
- 3 = C#
- 5 = E
- Symbol
- Aadd9
- Root
- A
- Quality
- Added ninth
- Family
- added
- Notes
- A B C# E
- Degree formula
1 9 3 5- Semitones from the root
0 2 4 7- Distinct pitch classes
- 4
- Interval structure
- Stacked from the root: 2 semitones, 2 semitones, 3 semitones
- Notation
- Written add9. Frequently used where a plain major triad would sound too bare, and common in pop and fingerstyle arrangements.
- Key
- A · A major / F# minor key signature
Formula
The chord tones in order from the root, with the interval each one forms above it.
| Degree | Note | Semitones | Interval from the root |
|---|---|---|---|
| 1 | A | 0 | Perfect unison |
| 9 | B | 2 | Major second |
| 3 | C# | 4 | Major third |
| 5 | E | 7 | Perfect fifth |
Inversions
An inversion is the same set of notes with a different one in the bass. The last column gives the distance of each note above the bass note, in semitones.
| Inversion | Bass note | Degree in the bass | Notes above the bass | Semitones above the bass |
|---|---|---|---|---|
| root position | A | 1 | A – B – C# – E | 0 2 4 7 |
| first inversion | B | 9 | B – C# – E – A | 0 2 5 10 |
| second inversion | C# | 3 | C# – E – A – B | 0 3 8 10 |
| third inversion | E | 5 | E – A – B – C# | 0 5 7 9 |
Playable voicings
These shapes were found by searching the fretboard of a standard-tuned guitar (E A D G B E) rather than copied from a chord book. The search allows every string to sound or to be muted, rejects any shape with a muted string between two sounding strings, rejects any shape whose fretted notes span more than four frets (a five-fret window), requires every chord tone to be present, and then sorts what remains with root-position shapes first and the most compact, lowest shapes next. The shapes shown are the first six of that ordering; other orderings are possible at the same frets.
| # | Shape (low string first) | Notes | Degrees | Bass | Span (frets) | Sounding strings |
|---|---|---|---|---|---|---|
| 1 | 5-7-7-6-5-7 | A E A C# E B | 1 5 1 3 5 9 | A | 2 | 6 |
| 2 | 5-2-2-2-2-5 | A B E A C# A | 1 9 5 1 3 1 | A | 3 | 6 |
| 3 | 5-2-2-4-2-5 | A B E B C# A | 1 9 5 9 3 1 | A | 3 | 6 |
| 4 | 5-4-2-4-2-5 | A C# E B C# A | 1 3 5 9 3 1 | A | 3 | 6 |
| 5 | 5-4-2-4-5-5 | A C# E B E A | 1 3 5 9 5 1 | A | 3 | 6 |
| 6 | 5-4-7-4-5-5 | A C# A B E A | 1 3 1 9 5 1 | A | 3 | 6 |
Shape numbers run from the lowest string to the highest, so the left-hand number is the sixth string (low E) in standard tuning. Multiple shapes are listed because a chord can be voiced several ways, and because a lower position is not always the better sounding one.
Related chords and scales
- KeyEverything in A
- ScaleA major
Related
- KeyKey of A
- ScaleA major
- ChordA6 — Sixth
- ChordAm6 — Minor sixth
- ChordA11 — Dominant eleventh
- DegreesA — degree map
- Neck mapA — note map
- ScaleA aeolian