Package leaflet · Information for the musician · Chord
B flat Seventh Sharp Nine Chord (B♭7♯9)
Gritty, funky and aggressive. The sharp ninth rubs against the major third, combining major and minor colours in one chord.
- B♭7♯9
- 5 notes
- x10121
1Composition: what it contains
B♭ – D – F – A♭ – C♯
- Symbol
- B♭7♯9
- Also written
- B♭7♯9, B♭7(♯9), B♭7+9
- Formula
- 1 3 5 ♭7 ♯9
- Same sound as
- A♯7♯9
| Degree | Note | Interval | Semitones |
|---|---|---|---|
| 1 | B♭ | unison | 0 |
| 3 | D | major third | 4 |
| 5 | F | perfect fifth | 7 |
| ♭7 | A♭ | minor seventh | 10 |
| ♯9 | C♯ | augmented ninth | 15 |
2Appearance: diagrams and sound
On the guitar
x10121open position
643334fret 3
686769fret 6
x-13-12-13-14-xfret 12On the ukulele
3244fret 2
6865fret 5
13-13-10-13fret 10On the piano
On the staff
On bass and as an arpeggio
3Indications: what it is used for
Famous in rock, funk, blues-rock and soul as a tonic dominant chord with attitude, and in jazz as an altered V7 resolving to I or i. Its sharp ninth is enharmonic to the minor third, so it suits minor-pentatonic soloing over a dominant groove. In jazz, the altered scale or half-whole diminished scale fits over it. It frequently appears in blues and funk vamps and as the V chord in minor ii–V–i progressions.
4Dosage: how to practise it
On guitar, learn the classic shape rooted on the fifth string (root, 3, ♭7, ♯9) and practise funk rhythms at 90–120 BPM, muting between hits. On piano, play the left-hand voicing 3-♭7-♯9 and the right-hand altered voicings. Practise iiø7–V7♯9–im and a twelve-bar blues with every chord as 7♯9. Arpeggiate the chord. Five to ten minutes daily. On piano, practise comping with short, accented hits. Try improvising with the blues scale over a 7♯9 vamp, then with the altered scale, to hear both colours.
5Warnings and common mistakes
The sharp ninth is not a minor third: it sits above the major third, which must also be present. Do not confuse 7♯9 with m7, which has no major third. Avoid placing the ♯9 below the third in voicings, which turns the sound into a muddy minor chord. In a major ii–V–I, the sharp ninth may clash with a melody containing the natural ninth. The symbol '7+9' is ambiguous; prefer 7♯9.
6Interactions with chords, scales and keys
Inversions
- Inversion 1 · B♭7♯9/D · D – F – A♭ – C♯ – B♭
- Inversion 2 · B♭7♯9/F · F – A♭ – C♯ – B♭ – D
- Inversion 3 · B♭7♯9/A♭ · A♭ – C♯ – B♭ – D – F
- Inversion 4 · B♭7♯9/C♯ · C♯ – B♭ – D – F – A♭
Scales to play over B♭7♯9
7Other presentations available
The same chord from every note
C7♯9 C♯7♯9 D7♯9 E♭7♯9 E7♯9 F7♯9 F♯7♯9 G7♯9 A♭7♯9 A7♯9 B7♯9
Other chords on B♭
B♭ B♭m B♭dim B♭aug B♭sus2 B♭sus4 B♭5 B♭6 B♭m6 B♭7 B♭maj7 B♭m7 B♭m7♭5 B♭dim7 B♭m(maj7) B♭7sus4 B♭add9 B♭m(add9) B♭6/9 B♭9 B♭maj9 B♭m9 B♭11 B♭m11 B♭13 B♭7♭9 B♭7♯5 B♭7♭5
Read this leaflet carefully before playing. Keep it near your instrument. Free to use, print and share for personal and educational use.