A#

Triads · A# root / B♭

A# / B♭

The brightest, most stable triad. The foundation of Western tonal music.

0 st4 st7 st

Notes in A#

BbRoot
D3rd
F5th

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

Major in All 12 Keys

Other Chords in A#

Related Triads

About the A# Chord

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

The brightest, most stable triad. The foundation of Western tonal music. Practising the A# 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.