A#m7b5 — A# half-diminished seventh chord
A diminished triad with a minor seventh added. Three minor thirds separated by a major third.
- 1 = A#
- b3 = C#
- b5 = E
- b7 = G#
- Symbol
- A#m7b5
- Root
- A#
- Quality
- Half-diminished seventh
- Family
- seventh
- Notes
- A# C# E G#
- Degree formula
1 b3 b5 b7- Semitones from the root
0 3 6 10- Distinct pitch classes
- 4
- Interval structure
- Stacked from the root: 3 semitones, 3 semitones, 4 semitones
- Notation
- Written m7b5 or with a slashed circle. The chord on the seventh degree of a major key, and the ii chord in a minor ii-V-i.
- Key
- A# · 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.
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 | A# | 0 | Perfect unison |
| b3 | C# | 3 | Minor third |
| b5 | E | 6 | Tritone |
| b7 | G# | 10 | Minor seventh |
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 | A# | 1 | A# – C# – E – G# | 0 3 6 10 |
| first inversion | C# | b3 | C# – E – G# – A# | 0 3 7 9 |
| second inversion | E | b5 | E – G# – A# – C# | 0 4 6 9 |
| third inversion | G# | b7 | G# – A# – C# – E | 0 2 5 8 |
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 | 6-4-6-6-5-4 | A# C# G# C# E G# | 1 b3 b7 b3 b5 b7 | A# | 2 | 6 |
| 2 | 6-4-6-6-5-6 | A# C# G# C# E A# | 1 b3 b7 b3 b5 1 | A# | 2 | 6 |
| 3 | 6-7-6-6-5-6 | A# E G# C# E A# | 1 b5 b7 b3 b5 1 | A# | 2 | 6 |
| 4 | 6-4-6-3-5-4 | A# C# G# A# E G# | 1 b3 b7 1 b5 b7 | A# | 3 | 6 |
| 5 | 6-4-6-3-5-6 | A# C# G# A# E A# | 1 b3 b7 1 b5 1 | A# | 3 | 6 |
| 6 | 6-7-6-6-5-4 | A# E G# C# E G# | 1 b5 b7 b3 b5 b7 | A# | 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 A#
- ScaleA# locrian
- ChordA#dim
- ChordEbm7
Related
- ChordA#dim — Diminished
- ChordE♭m7 — Minor seventh
- ChordA#dim7 — Diminished seventh
- ChordA#7 — Dominant seventh
- ChordA#maj7 — Major seventh
- DegreesBb — degree map
- Neck mapBb — note map
- KeyKey of Bb