Aadd9 Add9 Accord

Major triad with an added 9th (no 7th). Lush, open sound popular in pop.

Aadd9 Accord — Quick Answer & Harmonic Definition

The Aadd9 (Add9) chord consists of the notes A, C#, E, B. It is constructed from the root note A using the add9 interval formula (0–4–7–14 semitones).

Formula: 0 – 4 – 7 – 14
Notes
A – C# – E – B
Intervals (semitones)
0 – 4 – 7 – 14
Type
7th Chord

Aadd9 on Piano

Press highlighted keys simultaneously to play the Aadd9 chord.

R
A (Root (R))
2
C# (Major 3rd)
3
E (Perfect 5th)
4
B (Major 9th)

Aadd9 on Guitar

The Aadd9 chord uses notes A, C#, E, B. Build a voicing by finding these notes on any strings — root on the 6th string is a common starting point for barre chord shapes.

Interval Analysis

Degree Interval Name Semitones Note in A
Root Root (R) 0 A
3rd Major 3rd 4 C#
5th Perfect 5th 7 E
7th Major 9th 14 B

About the A Add9 Chord

The Aadd9 chord (A Add9) consists of 4 notes: A, C#, E, B. Major triad with an added 9th (no 7th). Lush, open sound popular in pop.

To build any add9 chord, apply intervals of 0, 4, 7, 14 semitones above the root. Starting from A: the notes land on A, C#, E, B.

Playing Aadd9 on Piano

Press A, C#, E, B simultaneously. In root position, A is lowest. First inversion places C# in the bass for a lighter sound; second inversion uses E as the bass note.

Common Chord Progressions Using Aadd9

  • I–IV–V: Aadd9 – Dadd9 – Eadd9 (blues and rock)
  • I–V–vi–IV: Aadd9 – E – F#m – D (pop staple)
  • I–vi–IV–V: Aadd9 – F#m – D – E (50s progression)

The Aadd9 Chord in Context

The Aadd9 (Add9) chord features a distinctive major triad with an added 9th (no 7th). lush, open sound popular in pop. built from the intervals 0–4–7–14. It provides rich harmonic color and tension across pop, jazz, classical, and contemporary compositions.

Other A Chords

A
Major
Am
Minor
A7
Dominant 7th
Amaj7
Major 7th
Am7
Minor 7th
Adim
Diminished

Add9 Chord in All 12 Keys

Cadd9 C#add9 Dadd9 D#add9 Eadd9 Fadd9 F#add9 Gadd9 G#add9 Aadd9 A#add9 Badd9
Virtual Piano
Play Aadd9 on piano
Virtual Guitar
See on the fretboard
A Scale
Notes that fit Aadd9
Songs
Find songs using Aadd9

Knowledge Base & FAQs

Aadd9 Chord — Frequently Asked Questions

Everything you need to know about our browser-based Web Audio engine, instruments, and music theory workspace.

What notes are in the Aadd9 chord?

The A Add9 chord contains: A, C#, E, B.

These notes are derived by applying the add9 interval formula (0–4–7–14 semitones) to the root note A.

What is the Aadd9 chord used for?

Major triad with an added 9th (no 7th).

Lush, open sound popular in pop. The Aadd9 chord is used across pop, rock, jazz, and classical music. As the I chord in the key of A major, it functions as the most stable resting point in progressions.

How do you play Aadd9 on piano?

On piano, play A, C#, E, B simultaneously.

In root position, A is the lowest note. Inversions move the bass note up — first inversion has C# lowest, second inversion has E lowest.

How many notes are in a add9 chord?

A add9 chord has 4 notes: A, C#, E, B (in A).

It is a 7th chord, extending beyond the basic triad.

What is the difference between A major and A minor?

The A major chord (A–C#–E) uses a major third (4 semitones), giving it a bright, happy sound.

The A minor chord (A–C–E) uses a minor third (3 semitones), giving it a darker, emotional sound.

What key does Aadd9 belong to?

Aadd9 naturally serves as the I chord in the key of A major.

It also appears as IV in the key of E major, and as V in the key of D major.

Can I play Aadd9 on ukulele?

Yes.

The ukulele uses GCEA tuning with 4 strings. The Aadd9 chord notes (A, C#, E, B) can be fretted on a ukulele, though the shapes differ from guitar due to the 4-string layout and shorter scale.

What chords go well with Aadd9?

In the key of A major, Aadd9 pairs naturally with D major (IV), E major (V), and F#m (vi).

The classic I–IV–V (Aadd9–D–E) is the foundation of blues, country, and rock.

What is a chord inversion of Aadd9?

An inversion places a non-root note in the bass.

Aadd9 root position: A in bass. First inversion: C# in bass. Second inversion: E in bass. Inversions create smoother bass line movement without changing the harmony.

How do I memorize the notes in a add9 chord?

Remember the formula: 0–4–7–14 semitones from root.

For Aadd9: start on A, add 4 semitones, then 7 semitones, then 14 semitones. Practicing this across all 12 roots builds instant recognition of any add9 chord.