Bass chord companion
Learn the A9 chord on bass with chord tones, intervals, playable arpeggios, and fretboard maps.
Play these tones one at a time to outline the chord. The maps show the complete formula; the numbered exercises give an ascending path, including extensions in their written octave.
Standard four-string bass: E1 – A1 – D2 – G2. String 4 is low E; string 1 is high G. Fingers 1–4 are index through little finger; 0 is open. Use comfortable hand positions and shift where indicated.
A Dominant 9th complete chord-tone map around string 4, fret 5. Choose individual tones for a bass line.
Follow steps 1–5 below. Keep one hand position.
| Step | Degree | Note | String / fret | Finger | Position |
|---|---|---|---|---|---|
| 1 | 1 | A1 | 4 / 5 | 4 | Fret 2 |
| 2 | 3 | C#2 | 3 / 4 | 3 | Fret 2 |
| 3 | 5 | E2 | 2 / 2 | 1 | Fret 2 |
| 4 | b7 | G2 | 1 / 0 | Open | Fret 2 |
| 5 | 9 | B2 | 1 / 4 | 3 | Fret 2 |
A Dominant 9th complete chord-tone map around string 3, fret 0. Choose individual tones for a bass line.
Follow steps 1–5 below. Keep one hand position.
| Step | Degree | Note | String / fret | Finger | Position |
|---|---|---|---|---|---|
| 1 | 1 | A1 | 3 / 0 | Open | Fret 1 |
| 2 | 3 | C#2 | 3 / 4 | 4 | Fret 1 |
| 3 | 5 | E2 | 2 / 2 | 2 | Fret 1 |
| 4 | b7 | G2 | 1 / 0 | Open | Fret 1 |
| 5 | 9 | B2 | 1 / 4 | 4 | Fret 1 |
Every A9 Chord chord tone across the neck, with roots highlighted for quick orientation.
Frets 0–24. Select a position or tap a note to hear it.
Try these progressions to hear the harmony in context. On bass, outline each chord with individual target tones.
Use the dominant sound to pull strongly into a stable major tonic.
The same dominant root can resolve into a minor tonic for a darker cadence.
Place the dominant at the end of a turnaround so the next phrase has forward motion.
| Degree | Interval | Note |
|---|---|---|
| 1 | Root | A |
| 3 | M3 | C# |
| 5 | P5 | E |
| b7 | m7 | G |
| 9 | M9 | B |
1 – 3 – 5 – b7 – 9
Compound degrees retain their names: 9, 11, and 13 are extensions. A voicing may place their pitches in a closer register.