Practice A#7b5 Guitar Chord: Interactive Fretboard & Ear Training
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The A#7b5 chord is A# seventh flat five: A#, C##, E and G#. It sounds identical to Bb7b5, which uses Bb, D, Fb and Ab, so that is the spelling charts usually print.
Three voicings are listed, one with a barre, and the lowest is at the 1st fret. The sharp version needs a double sharp for its major third, while its lowered fifth is a plain E. The A# whole-tone scale contains all four tones.
Press play above to listen to the chord strummed and arpeggiated, then try the flat-spelled twin for comparison.
A# 7th with flat 5th guitar chord is also written as A#7b5, A#7(b5) or A#7-5.
A#7b5 Chord Notes and Formula
Notes in the A# 7b5 chord:
Chord Formula:
Formula: 1 3 b5 b7
Same chord, different name: A#7b5 is also written as Bb7b5 (Bb seventh flat five).
A#7b5 Chord Interactive Fretboard
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A#7b5 Guitar Chord Diagrams
Position 1 Barre Movable
A# Seventh Flat Five Finger Positions
- Mute the low E string
- Mute the high E string
- Place your index finger (1) on the fret 1 of the A and G strings at the same time
- Place your middle finger (2) on the fret 2 of the D string
- Place your ring finger (3) on the fret 3 of the B string
Position 2 Movable Slash Chord
A#/G# Seventh Flat Five Finger Positions
- Mute the low E string
- Mute the A string
- Place your index finger (1) on the fret 5 of the B string
- Place your middle finger (2) on the fret 6 of the D string
- Place your ring finger (3) on the fret 6 of the high E string
- Place your pinky finger (4) on the fret 7 of the G string
The lowest note is G#, not the root, so this voicing is the slash chord A#7b5/G#.
Position 3 Movable
A# Seventh Flat Five Finger Positions
- Mute the low E string
- Mute the A string
- Place your index finger (1) on the fret 8 of the D string
- Place your middle finger (2) on the fret 9 of the G string
- Place your ring finger (3) on the fret 9 of the B string
- Place your pinky finger (4) on the fret 10 of the high E string
Find more shapes in our all guitar chords online library. If you
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Chords That Go With A#7b5
One key where A#7b5 fits is Eb major, where it works as the V chord (spelled Bb7b5 in that key), an altered chord whose Fb is borrowed from outside the key. These are the main chords of that key, the ones you will often hear around it:
See every key in the guitar keys chart, or build a progression with these chords in the chord progression generator.
More A# Chords
Want to know how this chord is built? Read dominant chords explained, or browse all A# guitar chords.
Created by
Giancarlo is a musician (teaching guitar since 2000), software engineer, AI consultant and published researcher
FAQ
What notes are in A#7b5?
A#7b5 is spelled A#, C##, E and G#. It is A#7 with the fifth lowered by a semitone, from E# to E.
Is A#7b5 the same chord as Bb7b5?
Yes. Bb7b5 is Bb, D, Fb and Ab, which sound as the same four pitches as A#, C##, E and G#. Bb7b5 is simpler to read, since it has no double sharp.
Why does A# seventh flat five contain a double sharp?
The major third over A# needs the letter C, and C# would be only a minor third. So the chord uses C##, which sounds like D.
What does the b5 in A#7b5 mean?
It is E, a diminished fifth over A#, which equals a tritone. It is the perfect fifth E# lowered by a semitone.
How many voicings does A#7b5 have?
There are 3 voicings, from fret 1 to fret 10. One of them is a barre voicing and none uses an open string.
