The A#m7b5 chord (A sharp minor 7 flat 5, or A sharp half diminished) contains the notes A#, C#, E and G#, which is the 1 (root) b3, b5 and b7 of the A# Major scale. It can be viewed as an A#m7 chord with a flat 5 or an A# diminished chord with an added b7.

The half diminished chord can sound like a very dissonant chord, when played in isolation. However, when played in the context of other chords, it can sound beautiful. A#m7b5 is the 7th chord in the key of B Major. Try playing a B chord, then an A#m7b5 chord and then return to B. This is an example of how A#m7b5 can sound beautiful in context.

The A#m7b5 chord is most commonly played with the root note on the 4th fret of the 6th string (2nd shape in the picture below).

10 Ways To Play The A#m7b5 Chord

If you’ve come to this page just to view some chord diagrams for A#m7b5 (A sharp half diminished), here they are.

A#m7b5 10 Shapes

Some Quick A#m7b5 Chord Theory

  • The A sharp minor 7 flat 5 chord contains the notes A#, C#, E and G#.
  • The A#m7b5 chord is produced by playing the 1st (root), flat 3rd, flat 5th and flat 7th of the A# Major scale.
  • The A sharp minor 7 flat 5 chord (just like all half diminished chords) contains the following intervals (from the root note): minor 3rd, minor 3rd, Major 3rd, Major 2nd (back to the root note).
  • A#m7b5 is an A# diminished chord, with an added flat 7th (G#) included, or an A#m7 chord with the 5th lowered by a semitone.
  • A#m7b5 is the 7th chord in the key of B.
  • The A# locrian mode can be used when soloing over the A#m7b5 chord.

Further Reading

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