Bass chord companion
Learn the A13b9 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 13b9 complete chord-tone map around string 4, fret 5. Choose individual tones for a bass line.
Follow steps 1–6 below. This path uses 1 marked position shift.
| Step | Degree | Note | String / fret | Finger | Position |
|---|---|---|---|---|---|
| 1 | 1 | A1 | 4 / 5 | 2 | Fret 4 |
| 2 | 3 | C#2 | 3 / 4 | 1 | Fret 4 |
| 3 | 5 | E2 | 3 / 7 | 4 | Fret 4 |
| 4 | b7 | G2 | 2 / 5 | 2 | Fret 4 |
| 5 | b9 | Bb2 | 2 / 8 | 1 | Shift to 8 |
| 6 | 13 | F#3 | 1 / 11 | 4 | Fret 8 |
A 13b9 complete chord-tone map around string 3, fret 0. Choose individual tones for a bass line.
Follow steps 1–6 below. This path uses 1 marked position shift.
| Step | Degree | Note | String / fret | Finger | Position |
|---|---|---|---|---|---|
| 1 | 1 | A1 | 3 / 0 | Open | Fret 4 |
| 2 | 3 | C#2 | 3 / 4 | 1 | Fret 4 |
| 3 | 5 | E2 | 3 / 7 | 4 | Fret 4 |
| 4 | b7 | G2 | 2 / 5 | 2 | Fret 4 |
| 5 | b9 | Bb2 | 2 / 8 | 1 | Shift to 8 |
| 6 | 13 | F#3 | 1 / 11 | 4 | Fret 8 |
Every A13b9 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 |
| b9 | m9 | Bb |
| 13 | M13 | F# |
1 – 3 – 5 – b7 – b9 – 13
Compound degrees retain their names: 9, 11, and 13 are extensions. A voicing may place their pitches in a closer register.