A#° (Diminished)

Bb · Db · E · 3 notes

Chord

Formula: R – ♭3 – ♭5

Bb R

Db ♭3

E ♭5

Bass note: Bb

Key	Degree
B Major	vii°
G# Minor	ii°

The A#° chord is a diminished chord built on A#. It consists of the notes Bb, Db, E (scale degrees R, ♭3, ♭5).

Diminished chords stack two minor 3rds (3+3 semitones), creating a tense, unresolved sound. They typically appear as the vii° in major keys.

Use the Key Finder to find what key these notes belong to, or the Progression Builder to use this chord in a sequence.