Aadd9 Chord on Guitar
Aadd9 = A – C# – E – B (Root, Major 3rd, Perfect 5th, Major 9th)
A add9 takes the plain A-major triad and layers a ninth on top without touching the seventh at all, producing a brighter, more modern-sounding chord than either plain A or the more jazz-flavored A9. At the fifth-fret barre it's one extra fretted note beyond the standard A-major shape.
The notes are A, C#, E, B — a complete major triad plus the ninth (the second, an octave higher, in harmonic terms). Because the seventh is absent, add9 keeps the chord's stability and major identity fully intact while still adding a shimmering upper color, which is exactly why it's such a common choice in pop, indie, and singer-songwriter guitar parts that want brightness without the tension a dominant or major-seventh chord would introduce. It functions in A-major progressions exactly the way plain A does, just dressed up.
Fingerings
Barre (5th fret)
How to Practice It
Play A, A add9, and A9 in sequence to hear clearly how each one changes the chord's mood — add9 stays bright and settled, while A9 introduces real dominant pull. This is a good chord for practicing controlled string muting, since the note being added sits close to open strings that can easily ring unintentionally if the fretting hand isn't precise.
Common Progressions
- A add9 – D (I add9 – IV, a bright verse-style move)
- F#m – A add9 – D – E (vi – I add9 – IV – V)
- A add9 – E – D (I add9 – V – IV)
- A add9 – A – D (contrasting the plain and colored tonic)
FAQ
- How is A add9 different from A9?
- A add9 keeps the plain major triad and adds only the ninth on top, with no seventh at all, while A9 is a full dominant chord that includes both the flat seventh and the ninth, giving it a much stronger tension-and-resolution character.
- Why is add9 popular in pop and indie guitar parts?
- It brightens a plain major chord without introducing the dissonance a seventh or dominant chord would, making it an easy, low-risk way to add color to a simple progression without changing its underlying function.
- Does A add9 need to resolve anywhere?
- No — unlike suspended or dominant chords, add9 is a stable major sonority in its own right and can sit comfortably as a tonic or any other diatonic chord without any pull to move.
- Is A add9 harder to play than plain A major?
- Only slightly — it's the same fifth-fret barre with one extra note added, comparable in difficulty to A6 or Asus2.
- Can A add9 substitute for plain A major throughout a whole song?
- Often yes, especially in genres that favor a fuller, more textured guitar sound, since add9 doesn't change the chord's harmonic function — it just adds brightness, so swapping it in for plain A rarely causes any clash with the rest of the progression.
- What's the easiest way to hear the added ninth?
- Strum plain A major, then A add9, and focus on the highest new pitch — the shimmer that appears is the ninth, and once it's identified by ear it becomes much easier to recognize add9 chords in other songs.
- Why do some charts write this as 'Aadd9' with no space or hyphen?
- It's just notational convention — 'add9' as a single unspaced suffix distinguishes it clearly from a plain '9' chord (which implies the seventh is present), a distinction that matters enough in practice that most chord charts are careful to keep the two symbols visually distinct.
Aadd9 on other instruments: Aadd9 on Piano, Aadd9 on Ukulele. Related: how chords are built, chord finder.