The A Minor 9th chord is a five-note chord made up of A, C, E, G, and B. It is built from a root, minor third, perfect fifth, minor seventh, and major ninth.
Construction
A Minor 9th = Root + Minor 3rd + Perfect 5th + Minor 7th + Major 2nd = A · C · E · G · B
| Note | Interval | Degree |
|---|---|---|
| A | Root | 1 |
| C | Minor 3rd | ♭3 |
| E | Perfect 5th | 5 |
| G | Minor 7th | ♭7 |
| B | Major 2nd | 9 |
Key Signature
A chord has no key signature of its own, but the A Minor 9th is the tonic (i) chord of A Minor, which shares the signature of its relative major, C Major — no sharps or flats.
Chords in the Key of A Minor
These are the triads built on each degree of the A minor scale:
A Minor 9th — Frequently Asked Questions
What is the A Minor 9th chord on piano?
The A Minor 9th chord contains the notes A – C – E – G – B. On piano, play these notes together to sound the chord.
What notes are in the A Minor 9th chord?
The A Minor 9th chord (Am9) contains five notes: A (root), C (minor third), E (perfect fifth), G (minor seventh), and B (major ninth). It is Am7 with an added ninth. Almost all white keys.
How does Am9 differ from A9?
Am9 has a minor third (C). A9 has a major third (C#). Am9 is dark and smooth; A9 is dominant and bluesy.
How is Am9 used in music?
Am9 is the ii in G Major (Am9–D13–Gmaj9) and the vi in C Major. It is one of the most common m9 chords in pop, jazz, and lo-fi because A minor and C Major are the most popular keys.
What songs use Minor 9th chords?
Minor 9th chords define neo-soul and lo-fi. Am9 may be the most frequently used m9 chord in popular music.
How does Am9 differ from Am7?
Am9 adds the ninth (B) for richer, more open colour.
Do I need to play all five notes?
No — drop the fifth: A–C–G–B is practical. Nearly all white keys.