A#maj9

Extended · A# root / B♭

A#maj9 / B♭maj9

Lush and expansive. Adds colour above the major 7th chord.

0 st4 st7 st11 st14 st

Notes in A#maj9

BbRoot
D3rd
F5th
A7th
C9th

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#maj9, A#m, A#7, or another quality — the hardest and most useful ear training skill.

Major 9th in All 12 Keys

Other Chords in A#

Related Extended

About the A#maj9 Chord

The A#maj9 chord is a major 9th chord built on A# (also written B♭maj9). It contains the notes Bb, D, F, A, C — the root, third, fifth, seventh, and extensions.

Lush and expansive. Adds colour above the major 7th chord. Practising the A#maj9 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.