Construction
| Note | Interval | Degree |
|---|---|---|
| A | Root | 1 |
| C | Minor 3rd | ♭3 |
| E | Perfect 5th | 5 |
| G | Minor 7th | ♭7 |
| B | Major 2nd | 9 |
Fingering
| Note | Key color | Right hand | Left hand |
|---|---|---|---|
| A | white | thumb (1) | little finger (5) |
| C | white | index finger (2) | ring finger (4) |
| E | white | middle finger (3) | middle finger (3) |
| G | white | ring finger (4) | index finger (2) |
| B | white | little finger (5) | thumb (1) |
Right hand: thumb (1) on A, index finger (2) on C, middle finger (3) on E, ring finger (4) on G, little finger (5) on B.
Left hand: little finger (5) on A, ring finger (4) on C, middle finger (3) on E, index finger (2) on G, thumb (1) on B.
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 A Minor:
Scales That Include the A Minor 9th
- C Major (vi)
- G Major (ii)
- A Minor (i)
- E Minor (iv)
- D Dorian (v)
- E Phrygian (iv)
- F Lydian (iii)
- G Mixolydian (ii)
A Minor 9th : Frequently Asked Questions
What is the A Minor 9th chord on piano?
What notes are in the A Minor 9th chord?
How does Am9 differ from A9?
How is Am9 used in music?
What songs use Minor 9th chords?
How does Am9 differ from Am7?
Do I need to play all five notes?
A Minor 9th in detail
Exact
Every pitch class is present and nothing outside the chord is added.
| Type | Notes | Semitones | Span | Omissions and additions | Set relation | Fit |
|---|---|---|---|---|---|---|
| Close, root position | A3 C4 E4 G4 B4 | 14 | 193 mm | none | identical | |
| Close, first inversion | C4 E4 G4 A4 B4 | 11 | 151 mm | none | identical | |
| Close, second inversion | E4 G4 A4 B4 C5 | 8 | 110 mm | none | identical | |
| Close, third inversion | G4 A4 B4 C5 E5 | 9 | 124 mm | none | identical | |
| Close, fourth inversion | B3 C4 E4 G4 A4 | 10 | 138 mm | none | identical | |
| Drop 2 | G3 A3 C4 E4 B4 | 16 | 220 mm | none | identical | |
| Drop 3 | E3 A3 C4 G4 B4 | 19 | 261 mm | none | identical | |
| Drop 2 and 4 | C3 G3 A3 E4 B4 | 23 | 316 mm | none | identical |
Reduced
A subset of the pitch classes: the identity is incomplete rather than altered.
| Type | Notes | Semitones | Span | Omissions and additions | Set relation | Fit |
|---|---|---|---|---|---|---|
| Shell, root 9 ♭3 | A2 B3 C4 | 15 | 206 mm | omits E | subset | |
| Guide tones, ♭3 and 9 | C4 B4 | 11 | 151 mm | omits A and E | subset | |
| Rootless close | C4 E4 G4 B4 | 11 | 151 mm | omits A | subset |
Spans are measured centre to centre at a 165 mm octave (standard keyboard geometry).
| Position | Bass note | Notes in order | Figured bass | Semitones | Span |
|---|---|---|---|---|---|
| Root position | A | A3, C4, E4, G4, B4 | 9 | 14 | 193 mm |
| First inversion: Am9/C | C | C4, E4, G4, A4, B4 | 7/6/5 | 11 | 151 mm |
| Second inversion: Am9/E | E | E4, G4, A4, B4, C5 | 7/4/3 | 8 | 110 mm |
| Third inversion: Am9/G | G | G4, A4, B4, C5, E5 | 7/4/2 | 9 | 124 mm |
| Fourth inversion: Am9/B | B | B3, C4, E4, G4, A4 | 9/7/5 | 10 | 138 mm |
One position per chord tone in the bass. Spans are for close position: voiced inversions appear under Voicings.
| Progression | Key | Role | Sequence | Voice leading |
|---|
Root motion, common tones and voice displacement are computed from pitch class sets. Roman numerals follow common practice functional harmony.
Change one note
Chords a single note away, and what moving that note does.
| Chord | Change | Formula | Common tones |
|---|---|---|---|
| Am7 | drops B | 1 ♭3 5 ♭7 | 4 |
| A9 | C becomes C♯ | 1 3 5 ♭7 9 | 4 |
| A7 | C, B becomes C♯ | 1 3 5 ♭7 | 3 |
| AmMaj7 | G, B becomes G♯ | 1 ♭3 5 7 | 3 |
| Am7♭5 | E, B becomes E♭ | 1 ♭3 ♭5 ♭7 | 3 |
| A7sus4 | C, B becomes D | 1 4 5 ♭7 | 3 |
| Am6 | G, B becomes F♯ | 1 ♭3 5 6 | 3 |
| Aadd9 | C, G becomes C♯ | 1 3 5 9 | 3 |
| Amaj9 | C, G becomes C♯, G♯ | 1 3 5 7 9 | 3 |
Frequencies
| Note | MIDI | Frequency |
|---|---|---|
| A3 | 57 | 220.00 Hz |
| C4 | 60 | 261.63 Hz |
| E4 | 64 | 329.63 Hz |
| G4 | 67 | 392.00 Hz |
| B4 | 71 | 493.88 Hz |
Reference pitch A440, 12-TET, close root position.
Set theory: prime form, Forte number, interval vector
- Absolute pitch class set
- {9, 0, 4, 7, 11}
- Normal order
- [4, 7, 9, 11, 0]
- Prime form
- (01358)
- Forte number
- not claimed for this cardinality
- Interval vector
- <122230>
| Pair | Interval | Semitones | Interval class |
|---|---|---|---|
| A to C | Minor third | 3 | 3 |
| A to E | Perfect fifth | 7 | 5 |
| A to G | Minor seventh | 10 | 2 |
| A to B | Major ninth | 14 | 2 |
| C to E | Major third | 4 | 4 |
| C to G | Perfect fifth | 7 | 5 |
| C to B | Major seventh | 11 | 1 |
| E to G | Minor third | 3 | 3 |
| E to B | Perfect fifth | 7 | 5 |
| G to B | Major third | 4 | 4 |
Where these facts come from
Every value on this page is derived from the note formula for a minor 9th applied to the root A, using standard music theory. Nothing here is hand-entered per chord, so the notes, intervals, inversions and frequencies cannot drift out of agreement with each other. Pitches assume 12-TET at A440.