Extended · A# root / B♭
A#13 / B♭13
The fullest dominant extension. Contains almost every scale degree.
Notes in A#13
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#13, A#m, A#7, or another quality — the hardest and most useful ear training skill.
13th in All 12 Keys
Other Chords in A#
Related Extended
About the A#13 Chord
The A#13 chord is a 13th chord built on A# (also written B♭13). It contains the notes Bb, D, F, Ab, C, Eb, G — the root, third, fifth, seventh, and extensions.
The fullest dominant extension. Contains almost every scale degree. Practising the A#13 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.