B+9 — B augmented ninth chord
An augmented triad with the ninth added. The three augmented notes divide the octave equally, and the ninth sits a whole tone above the root.
- 1 = B
- 3 = D#
- #5 = F##
- 9 = C#
- Symbol
- B+9
- Root
- B
- Quality
- Augmented ninth
- Family
- altered
- Notes
- B D# F## C#
- Degree formula
1 3 #5 9- Semitones from the root
0 2 4 8- Distinct pitch classes
- 4
- Interval structure
- Stacked from the root: 4 semitones, 4 semitones, 6 semitones
- Notation
- Written +9 or aug9. Used as a bright tonic or as an altered dominant where the seventh is supplied by another instrument.
- Key
- B · B major / G# minor key signature
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 | B | 0 | Perfect unison |
| 3 | D# | 4 | Major third |
| #5 | F## | 8 | Minor sixth |
| 9 | C# | 2 | Major 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 | B | 1 | B – D# – F## – C# | 0 4 8 2 |
| first inversion | D# | 3 | D# – F## – C# – B | 0 4 10 8 |
| second inversion | F## | #5 | F## – C# – B – D# | 0 6 4 8 |
| third inversion | C# | 9 | C# – B – D# – F## | 0 10 2 6 |
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 | 7-4-5-4-4-7 | B C# G B D# B | 1 9 #5 1 3 1 | B | 3 | 6 |
| 2 | 7-4-5-6-4-7 | B C# G C# D# B | 1 9 #5 9 3 1 | B | 3 | 6 |
| 3 | 7-6-5-6-4-7 | B D# G C# D# B | 1 3 #5 9 3 1 | B | 3 | 6 |
| 4 | 7-6-5-6-8-7 | B D# G C# G B | 1 3 #5 9 #5 1 | B | 3 | 6 |
| 5 | 7-6-9-6-8-7 | B D# B C# G B | 1 3 1 9 #5 1 | B | 3 | 6 |
| 6 | 7-6-9-6-8-9 | B D# B C# G C# | 1 3 1 9 #5 9 | B | 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 B
- ScaleB whole tone
- ChordBaug
- ChordB
- ChordB7
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