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Key of A#

The key of A♯ major is theoretical — written out it would need double sharps, so musicians use its enharmonic twin, B♭ major. Everything below is shown for B♭ major. Go to B♭ major →

A♯ major is the same key as B♭ major. The key of B♭ major has two flats (B♭, E♭). Its seven notes are B♭, C, D, E♭, F, G, and A. Its relative minor is G Minor, which shares the same notes and key signature. The chords that belong to the key are I B♭ major, ii C minor, iii D minor, IV E♭ major, V F major, vi G minor, vii° A diminished. Its dominant is F major and its subdominant is E♭ major — the keys it most naturally moves toward. Keys built on flats, like B♭ major, are traditionally described as warm and mellow.

Key Signature

The notes of the Bb Major come from Bb Major, so it carries that key signature: 2 flats (B♭, E♭).

B♭E♭

Order of flats

Flats are added in a fixed order — the reverse of the sharp order. Each new flat key adds the next flat on the list.

BEADGCF

Mnemonic: Battle Ends And Down Goes Charles’ Father

Relative minor: G Minor scale — same notes, same key signature, different home note.

Chords in the Key of B♭ Major

Every major key is built from seven diatonic chords — one on each note of the scale. In B♭ major they are I B♭ Major, ii C Minor, iii D Minor, IV E♭ Major, V F Major, vi G Minor, and vii° A Diminished. Tap any chord to light it up on the keyboard.

C1C2C3C4C5DFC6C7C8A#
IB♭ Major (major)

Common chord progressions in B♭ major

  • I – IV – VB♭E♭Fthe three primary chords
  • I – V – vi – IVB♭FGE♭the most common pop progression
  • ii – V – ICFB♭the backbone of jazz
  • I – vi – IV – VB♭GE♭Fthe classic doo-wop turnaround

Everything in the key of A#

Every chord, scale, and mode in A# — click any link for the full interactive page with piano diagrams, audio, notation, and fingerings.

A# Chords

A# Scales

A# Modes