Chords
A Major ninth
A · C# · E · G# · B
The major ninth chord — a maj7 with a ninth on top. The most luxuriant of the stable chords.
Also written AΔ9 · A^9
A Major ninth
A · C# · E · G# · B
Voicings on the piano
| Voicing | Notes | Play it on your instrument |
|---|---|---|
| Closed, root position | A3 · C#4 · E4 · G#4 · B4 | |
| Open (drop 2) | G#3 · A3 · C#4 · E4 · B4 | |
| Shell | A3 · C#4 · G#4 | |
| Rootless | C#3 · G#3 · B3 |
Tap a key or a fret to hear it.
Anatomy
A Major ninth (Amaj9) contains the notes A · C# · E · G# · B, each with a role measured as an interval from the root.
Read on: how triads are built · seventh chords · extensions
Inversions
An inversion of A Major ninth puts a chord tone other than A in the bass; the name after the slash is that bass note.
Where it lives
The keys and the scales A Major ninth belongs to.
In which keys
A Major ninth is diatonic to 4 keys; the numeral is its degree and the label its harmonic function.
Extensions beyond the seventh count when every note sits in the key.
Scales that contain it
A Major ninth fits inside these scales, each built on A.
- A MajorA · B · C# · D · E · F# · G#
- A LydianA · B · C# · D# · E · F# · G#
- A Harmonic MajorA · B · C# · D · E · F · G#
- A BebopA · B · C# · D · E · F# · G · G#
- A Bebop MajorA · B · C# · D · E · E# · F# · G#
- A IchikosuchoA · B · C# · D · Eb · E · F# · G#
- A Messiaen's Mode #3A · B · C · C# · D# · E · F · G · G#
Understanding the A Major ninth chord
Names and symbols
Amaj9 is the chord symbol for A Major ninth; it is also written AΔ9, A^9.
add9, 9 and maj9 are three different chords. add9 adds a ninth to a plain triad with no seventh; 9 is a dominant seventh with a ninth; maj9 is a major seventh with a ninth.
How it is built
On A it is A · C# · E · G# · B, stacking 1P · 3M · 5P · 7M · 9M. It is the maj7 with one more third added above.
How it is used
Neo-soul, bossa nova and modern gospel use it as the tonic. It carries the same stability as a maj7 with more air, and because it contains no tritone it never insists on going anywhere.
Learn this properly
Chapter 10: Chords: Triads and SeventhsCommon questions
- What notes are in Amaj9?
- Amaj9 contains A · C# · E · G# · B. Name any set of notes with the chord identifier.
- What is the difference between maj9 and add9?
- The seventh. maj9 includes the major seventh; add9 adds the ninth to a plain triad and leaves the seventh out.
- Which voicing is usual?
- Pianists commonly drop the fifth and often the root, voicing third, seventh and ninth — enough to state the chord without crowding it.
- What notes are in the A Major ninth chord?
- The A Major ninth chord contains the notes A · C# · E · G# · B: the root A with the intervals 1P, 3M, 5P, 7M, 9M stacked above it. Play them together for the chord or one after another for an arpeggio. The lowest note is normally A, but any chord tone can take the bass in an inversion.
- What intervals make up the A Major ninth chord?
- Measured from A, the A Major ninth chord stacks the intervals 1P, 3M, 5P, 7M, 9M. The quality of the third and of the seventh, if there is one, is what gives the chord its character; the rest of the notes colour it. Every interval in the formula links to its own page, with its sound.