Bb7♭9 — Bb dominant seventh flat ninth chord

A dominant seventh chord with the ninth flattened. The flat ninth sits a semitone above the root in the octave above, and the chord resolves down a fifth.

1 = Bb
3 = D
5 = F
b7 = Ab
b9 = Cb

Symbol: Bb7♭9
Root: Bb
Quality: Dominant seventh flat ninth
Family: altered
Notes: Bb D F Ab Cb
Degree formula: 1 3 5 b7 b9
Semitones from the root: 0 1 4 7 10
Distinct pitch classes: 5
Interval structure: Stacked from the root: 4 semitones, 3 semitones, 3 semitones, 3 semitones
Notation: Written 7♭9. The dominant of a minor key, because the flat ninth belongs to the harmonic minor scale of the target.
Key: Bb · Bb major / G minor key signature

Fingering charts

The library holds 6 fingerings of this chord and all of them are shown, in the library’s own order. Several fingerings of one chord is normal: the same notes can be stopped at different positions and on different strings.

Bb7♭9 chord fingering chart, variation 1 of 6 — Variation 1 of 6 Diagram: Will Chan

Bb7♭9 chord fingering chart, variation 2 of 6 — Variation 2 of 6 Diagram: Will Chan

Bb7♭9 chord fingering chart, variation 3 of 6 — Variation 3 of 6 Diagram: Will Chan

Bb7♭9 chord fingering chart, variation 4 of 6 — Variation 4 of 6 Diagram: Will Chan

Bb7♭9 chord fingering chart, variation 5 of 6 — Variation 5 of 6 Diagram: Will Chan

Bb7♭9 chord fingering chart, variation 6 of 6 — Variation 6 of 6 Diagram: Will Chan

Formula

The chord tones in order from the root, with the interval each one forms above it.

Degree	Note	Semitones	Interval from the root
1	Bb	0	Perfect unison
3	D	4	Major third
5	F	7	Perfect fifth
b7	Ab	10	Minor seventh
b9	Cb	1	Minor second

Inversions

An inversion is the same set of notes with a different one in the bass. The last column gives the distance of each note above the bass note, in semitones.

Inversion	Bass note	Degree in the bass	Notes above the bass	Semitones above the bass
root position	Bb	1	Bb – D – F – Ab – Cb	0 4 7 10 1
first inversion	D	3	D – F – Ab – Cb – Bb	0 3 6 9 8
second inversion	F	5	F – Ab – Cb – Bb – D	0 3 6 5 9
third inversion	Ab	b7	Ab – Cb – Bb – D – F	0 3 2 6 9
fourth inversion	Cb	b9	Cb – Bb – D – F – Ab	0 11 3 6 9

Inversion

Bass note

Degree in the bass

Notes above the bass

Semitones above the bass

root position

Bb – D – F – Ab – Cb

0 4 7 10 1

first inversion

D – F – Ab – Cb – Bb

0 3 6 9 8

second inversion

F – Ab – Cb – Bb – D

0 3 6 5 9

third inversion

Ab – Cb – Bb – D – F

0 3 2 6 9

fourth inversion

Cb – Bb – D – F – Ab

0 11 3 6 9

Playable voicings

These shapes were found by searching the fretboard of a standard-tuned guitar (E A D G B E) rather than copied from a chord book. The search allows every string to sound or to be muted, rejects any shape with a muted string between two sounding strings, rejects any shape whose fretted notes span more than four frets (a five-fret window), requires every chord tone to be present, and then sorts what remains with root-position shapes first and the most compact, lowest shapes next. The shapes shown are the first six of that ordering; other orderings are possible at the same frets.

#	Shape (low string first)	Notes	Degrees	Bass	Span (frets)	Sounding strings
1	6-5-6-4-6-4 (6→1)	Bb D Ab B F Ab	1 3 b7 b9 5 b7	Bb	2	6
2	6-5-6-4-6-6 (6→1)	Bb D Ab B F Bb	1 3 b7 b9 5 1	Bb	2	6
3	6-5-6-7-6-7 (6→1)	Bb D Ab D F B	1 3 b7 3 5 b9	Bb	2	6
4	6-8-6-7-6-7 (6→1)	Bb F Ab D F B	1 5 b7 3 5 b9	Bb	2	6
5	6-5-3-4-3-4 (6→1)	Bb D F B D Ab	1 3 5 b9 3 b7	Bb	3	6
6	6-5-3-4-6-4 (6→1)	Bb D F B F Ab	1 3 5 b9 5 b7	Bb	3	6

Shape numbers run from the lowest string to the highest, so the left-hand number is the sixth string (low E) in standard tuning. Multiple shapes are listed because a chord can be voiced several ways, and because a lower position is not always the better sounding one.

Related chords and scales

KeyEverything in Bbscale, chords and neck map for this root
ScaleBb diminished (half-whole)the scale this chord comes from
ChordBb7the dominant seventh it extends
ChordBbthe triad underneath it

Everything in Bb · All chords

KeyKey of BbBb C D Eb F G A · Bb major / G minor
ScaleBb diminished (half-whole)8 notes · 1 b2 b3 3 #4 5 6 b7
ChordBb7 — Dominant seventh1 3 5 b7 · Bb D F Ab
ChordBb — Major1 3 5 · Bb D F
ChordBb7b5 — Dominant seventh flat five1 3 b5 b7 · Bb D Fb Ab
ChordBb7♭5#9 — Dominant seventh flat fifth sharp ninth1 3 b5 b7 #9 · Bb D Fb Ab C#
ChordBb7#11 — Dominant seventh sharp eleventh1 3 5 b7 #11 · Bb D F Ab E
DegreesBb — degree mapBb major and natural minor · frets 0–22

Everything in this key: Bb · Chords · Theory Atlas