Amaj9 on the piano is a major 9th chord made from A, C#, E, G#, B. On piano it is played from the keys A, C#, E, G#, B, root position first, then in inversions. Below you will find its notes and intervals, every usable voicing on the piano, the common mistakes players make with it and the keys and progressions where it belongs.
What notes are in the Amaj9 chord?
The Amaj9 chord is a major 9th chord, and its notes are fixed: A, C#, E, G#, B. Every voicing on every instrument uses these same notes, in some order and in some octave — change one of them and you are playing a different chord. The table below lists each note with its interval from the root A, so you can see the structure of Amaj9 at a glance. On the piano, play the keys A, C#, E, G#, B slowly and listen for each note of Amaj9 in turn.
| Note | Interval |
|---|---|
| A | Root |
| C# | 3 |
| E | 5 |
| G# | 7 |
| B | 9 |
The root is A, the note the chord is named after and the note your ear hears as home. Above it, the intervals in Amaj9 are 3, 5, 7, 9. Those intervals are the fingerprint of the major 9th quality — any chord with the same interval pattern, on any root, is the same kind of chord. On the piano, the notes appear in the order the fingering dictates, but the set of notes never changes.
Amaj9 sounds lush, dreamy and wide open — the major 9th is one of the prettiest chords in popular music. Listen for that character when you play it — if Amaj9 does not sound that way, one of the notes is probably wrong, and the table above is the place to check. On the piano, the root-position keys A, C#, E, G#, B show Amaj9 most clearly.
Comparing Amaj9 with its closest relatives helps to fix it in your ear. In short, major 9th against dominant 9th: Amaj9 keeps the major 7th G#; the dominant 9th flattens it to G. The major 9th sounds dreamy; the dominant 9th sounds bluesy. Practise the two chords back to back and listen to the one note that changes — that single note is the difference between the two chords. On the piano, the root-position keys A, C#, E, G#, B show Amaj9 most clearly.
How to play Amaj9 on piano
On the piano, Amaj9 is played from the keys A, C#, E, G#, B. In root position the lowest note is A, the root, with the other notes stacked above it in the order A, C#, E, G#, B. Play it with the right hand first, then with the left hand an octave lower, so both hands know the shape of Amaj9 before you try it in a progression.
First inversion of Amaj9 puts C# in the bass, with the notes in the order C#, E, G#, B, A. The chord is still Amaj9 — the notes have not changed, only their order — but the bass note changes how it connects to the chord before and after it. Use this inversion when the bass line wants to step to C# rather than jump to A, and practise moving from root position to this inversion without lifting your hand off the keys more than you must.
Second inversion of Amaj9 puts E in the bass, with the notes in the order E, G#, B, A, C#. The chord is still Amaj9 — the notes have not changed, only their order — but the bass note changes how it connects to the chord before and after it. Use this inversion when the bass line wants to step to E rather than jump to A, and practise moving from root position to this inversion without lifting your hand off the keys more than you must.
Third inversion of Amaj9 puts G# in the bass, with the notes in the order G#, B, A, C#, E. The chord is still Amaj9 — the notes have not changed, only their order — but the bass note changes how it connects to the chord before and after it. Use this inversion when the bass line wants to step to G# rather than jump to A, and practise moving from root position to this inversion without lifting your hand off the keys more than you must.
Because Amaj9 has 5 notes, it has further inversions beyond the third, each one putting a different chord tone in the bass. The principle stays the same: the notes are always A, C#, E, G#, B, and the inversion you choose is the one whose bass note makes the smoothest line through the progression. Try the Chord Inverter to see every inversion of Amaj9 on the keyboard.
For fingering, a good starting point for Amaj9 in root position in the right hand is thumb on A, then one finger per note in order, with the little finger on the top note B. For the left hand, mirror it: little finger on the low A and thumb on the top note. When a note is a black key — C#, G# — let your longer fingers take it, since they reach the black keys more easily. Practise Amaj9 in root position and first inversion, hands separately, then together, at a slow tempo, and use the Piano Chord Finder to check the voicing on the keyboard.
Common mistakes
These are the mistakes that most often make Amaj9 sound wrong on the piano, and each one has a concrete fix. Work through them one at a time rather than trying to fix everything at once.
Playing every inversion with the same hand shape. Each inversion of Amaj9 needs its own hand shape, because the notes sit under different fingers. If you force the root-position fingering onto an inversion, the hand cramps and notes get missed. Learn the fingering for each inversion of Amaj9 separately, hands apart, before you join them. On the piano, the root-position keys A, C#, E, G#, B show Amaj9 most clearly.
Flattening the 7th. If the 7th is G instead of G#, the chord becomes a dominant 9th with a different function. Keep the 7th major. On the piano, Amaj9 is the keys A, C#, E, G#, B, and the inversions above move the same notes around.
Crowding five notes. Five notes need space. Drop the 5th (E) and spread the rest across octaves so the 9th B can ring. On the piano, play the keys A, C#, E, G#, B slowly and listen for each note of Amaj9 in turn.
Playing it too fast. Amaj9 is a slow chord. At a fast tempo its colour gets lost; give each note time to sound. On the piano, play the keys A, C#, E, G#, B slowly and listen for each note of Amaj9 in turn.
Where Amaj9 is used
Amaj9 is not a diatonic triad in any major or minor key, because it is an extended or altered chord, but its base triad belongs to the key of D major, the key of E major, the key of A major. the I or IV chord in major keys, the richest-sounding tonic colour available. As a dominant-type chord it also points toward D major, the key a perfect fourth above A, which is the tonic it most often resolves to. That is where Amaj9 does its work: not as a home chord, but as a chord that creates movement and then resolves. On the piano, play the keys A, C#, E, G#, B slowly and listen for each note of Amaj9 in turn.
Because Amaj9 is an extended or altered chord, it appears in progressions as a colour or a dominant rather than as a diatonic staple. Try it in place of the plain A triad in a progression you already know, and listen to how the extra notes change the feel — that substitution is the usual way extended chords enter real music. The Chord Progression Builder lets you try Amaj9 in a progression in any key and hear how it connects to the chords around it. On the piano, the root-position keys A, C#, E, G#, B show Amaj9 most clearly.
The same chord on other instruments is covered in Amaj9 on guitar, Amaj9 on ukulele, Amaj9 on bass, and the scales that fit over it are the A major scale and the A minor pentatonic scale. Learning Amaj9 on the piano and then checking it on another instrument is one of the best ways to fix the notes — A, C#, E, G#, B — in your memory, because the notes stay the same while everything else changes.
Practising Amaj9
A short worked example makes Amaj9 concrete. Play the four-chord progression D – A – Bm – G in D major, the key Amaj9 most often resolves toward: D – A – Bm – G. Play each chord for one bar at a slow tempo, and listen to how Amaj9 sounds in that sequence — whether it feels like home, like a lift, or like a chord on its way somewhere else. Then play the same four chords in a different order, starting on Amaj9 itself, and notice how its character changes when it opens the progression instead of sitting inside it. On the piano, the root-position keys A, C#, E, G#, B show Amaj9 most clearly.
For a second exercise, play Amaj9 and then the chord a fourth above A, back and forth, four times each. That move — a chord and the chord a fourth above it — is the most common resolution in Western music, and it is the move Amaj9 is built for when it acts as a dominant. Finish by playing Amaj9 on its own, slowly, and naming each note out loud as you play it: A, C#, E, G#, B. Naming the notes while you play them is what turns a shape into knowledge you can use in any key. Test yourself with the Practice Chord Quiz and keep time with the Metronome as the tempo rises. On the piano, play the keys A, C#, E, G#, B slowly and listen for each note of Amaj9 in turn.
Frequently asked questions
What notes are in Amaj9?
Amaj9 contains A, C#, E, G#, B: root A, major 3rd C#, perfect 5th E, major 7th G# and the 9th B. It is a major 7th chord with the 9th added on top. On the piano, the keys above put that note under your fingers.
Is Amaj9 a major chord?
Yes — a major 9th chord, built on a major triad with a major 7th and a 9th. It sounds major, lush and dreamy, and it works as a tonic chord. On the piano, the keys above put that note under your fingers.
What is the difference between Amaj9 and Amaj7?
Amaj9 adds the 9th B to the major 7th chord. That extra note widens the sound and makes the chord feel more open and spacious. On the piano, the keys above put that note under your fingers.
How do you play Amaj9 on the piano?
In root position, play the keys A, C#, E, G#, B, with A as the lowest note. That is the basic shape of Amaj9 on the piano. The inversions above put a different note in the bass, and the Chord Inverter shows every inversion of Amaj9 on the keyboard.
What is the first inversion of Amaj9?
The first inversion of Amaj9 puts C# in the bass, with the notes in the order C#, E, G#, B, A. The chord is still Amaj9 — only the bass note has changed — and it is the inversion to use when the bass line steps to C#.