The A#9 (A sharp 9) chord contains the notes A#, Cx, E#, G# and B#. It is produced by taking the 1 (root), 3, 5, b7 and 9 of the A# Major scale. The 9th note of the scale (B#) is the same as the 2nd note, but we refer to it as a 9, as this implies that the chord is a dominant 7 chord (1, 3, 5, 7) with a 9 included.

The 9th chord is a very popular guitar chord in Jazz, Funk and Blues. It is in many ways, the go-to ‘funk’ chord. The 9th chord can often be substituted for a dominant 7 chord. Let’s take an example chord progression:

Try playing this chord progression. After a while, try substituting the A#7 chord for a A#9 chord. You should hear that the chord progression sounds very similar, but the inclusion of the A#9 chord gives the chord progression a jazzy sound.

The most common way to play A#9 is with the root note on the 13th fret of the 5th string (second shape in the pic below).

10 Ways To Play The A#9 Chord

If you’ve come to this page just to view some chord diagrams for A#9, here they are.

A Sharp 9 Chord 10 Shapes

Some Quick A#9 Chord Theory

  • The A#9 chord contains the notes A#, Cx, E#, G# and B#.
  • The A#9 chord is produced by taking the 1 (root), 3, 5, b7 and 9 of the A# Major scale.
  • The 9th note of the A# Major scale (B#) is the same as the 2nd note of the scale.
  • The A#9 can be used as a substitute for the A#7 chord.
  • The A#9 is essentially an A sharp dominant 7 chord with an added 9.
  • The A# mixolydian mode can be used when soloing over the A#9 chord.

Further Reading

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