What notes are in the Aadd9 chord?

Aadd9 is made of A, C#, E and B — the 1, 3, 5 and 9 degrees of an add9 chord built on A.

What keys use the Aadd9 chord?

Every note of Aadd9 belongs to 6 keys: D Major (V), A Major (I), E Major (IV), B Minor (VII), F# Minor (III), C# Minor (VI). The roman numeral is the scale degree the chord is rooted on.

How do you play Aadd9 on guitar and piano?

This page shows Aadd9 on guitar, piano, ukulele and mandolin — 11 voicings in total. Each diagram links to the full instrument page with alternate shapes, audio and common mistakes.

Is Aadd9 the same as Aadd9?

Yes. Aadd9 and Aadd9 are enharmonic — identical pitches written two different ways. Which spelling you use depends on the key you are in; Aadd9 is the spelling this site treats as canonical.

Chord · Aadd9

Aadd9 Chord

Aadd9 is A, C#, E and B — major triad with an added 9th; pop and folk staple.

Hear it

Aadd9 on every instrument

The same 4 notes, 4 sets of hands. Open a diagram for alternate shapes, audio and the mistakes to avoid.

What Aadd9 is made of

Aadd9 (A add9) is built from the notes A, C#, E, B, with the interval pattern 1, 3, 5, 9.

Stack 1, 3, 5 and 9 on a root of A and you get A, C#, E and B. That interval recipe is what makes the chord an add9 chord — move the same shape to another root and the character travels with it, which is why F♯add9 sounds like a transposed Aadd9.

Add 9: Major triad with an added 9th; pop and folk staple.

Spelling: the notes above are written the way a score would write them, not simplified to the nearest piano key. That is why this chord is spelled with C♯ rather than its enharmonic equivalent.

Keys that contain Aadd9

All 4 notes sit inside the scale of 6 keys. The roman numeral marks the degree the chord is rooted on.

Major keys

Minor keys

Other chords on A

Same root, different colour.

AA Major AmA Minor AdimA Diminished AaugA Augmented Asus2A Suspended 2nd Asus4A Suspended 4th A5A Power Chord A6A Major 6th

The same add9 shape, moved

The identical interval recipe, built on other roots.

F♯add9F# Add 9 D♭add9Db Add 9 E♭add9Eb Add 9 A♭add9Ab Add 9 B♭add9Bb Add 9 Cadd9Cadd9 Dadd9Dadd9 Eadd9Eadd9

Questions people ask about Aadd9

What notes are in the Aadd9 chord?: Aadd9 is made of A, C#, E and B — the 1, 3, 5 and 9 degrees of an add9 chord built on A.
What keys use the Aadd9 chord?: Every note of Aadd9 belongs to 6 keys: D Major (V), A Major (I), E Major (IV), B Minor (VII), F# Minor (III), C# Minor (VI). The roman numeral is the scale degree the chord is rooted on.
How do you play Aadd9 on guitar and piano?: This page shows Aadd9 on guitar, piano, ukulele and mandolin — 11 voicings in total. Each diagram links to the full instrument page with alternate shapes, audio and common mistakes.
Is Aadd9 the same as Aadd9?: Yes. Aadd9 and Aadd9 are enharmonic — identical pitches written two different ways. Which spelling you use depends on the key you are in; Aadd9 is the spelling this site treats as canonical.

Learn the theory behind it

Why Aadd9 behaves the way it does — the guides that explain the chord instead of just spelling it.

Chord Inversions and Slash Chords — Same Notes, Different AttitudeSuspending or adding a tone is a voicing decision, the same kind as an inversion or a slash chord.5 min read Chord Progressions ExplainedThese chords earn their keep inside a progression, leaning on the plain chord that follows.7 min read Intervals — The Only Music Theory You Actually NeedWhich degree got swapped in, and what that one interval changes.5 min read