Extended · A# root / B♭
A#9 / B♭9
A dominant 7th with an added 9th. Funky and full of energy.
Notes in A#9
A# / Bb is a favourite for horn players and jazz musicians. Many blues and jazz standards are in Bb.
Identify the Chord Quality on A#
Each chord below is played on A#. Listen and identify whether you heard A#9, A#m, A#7, or another quality — the hardest and most useful ear training skill.
Dominant 9th in All 12 Keys
Other Chords in A#
Related Extended
About the A#9 Chord
The A#9 chord is a dominant 9th chord built on A# (also written B♭9). It contains the notes Bb, D, F, Ab, C — the root, third, fifth, seventh, and extensions.
A dominant 7th with an added 9th. Funky and full of energy. Practising the A#9 chord across different voicings and contexts builds the harmonic recognition that lets you identify it instantly in any musical setting — whether in a band mix, a recording, or a live performance.