What notes are in the Bb9 chord?

Bb9 is made of Bb, D, F, Ab and C — the 1, 3, 5, b7 and 9 degrees of a ninth chord built on Bb.

What keys use the Bb9 chord?

Every note of Bb9 belongs to 2 keys: Eb Major (V), C Minor (VII). The roman numeral is the scale degree the chord is rooted on.

How do you play Bb9 on guitar and piano?

This page shows Bb9 on guitar, piano, ukulele and mandolin — 8 voicings in total. Each diagram links to the full instrument page with alternate shapes, audio and common mistakes.

Is Bb9 the same as A#9?

Yes. Bb9 and A#9 are enharmonic — identical pitches written two different ways. Which spelling you use depends on the key you are in; Bb9 is the spelling this site treats as canonical.

Chord · Bb Dominant 9th

B♭9 Chord

B♭9 is Bb, D, F, Ab and C — funky, soulful; James Brown territory.

Hear it

B♭9 on every instrument

The same 5 notes, 4 sets of hands. Open a diagram for alternate shapes, audio and the mistakes to avoid.

What B♭9 is made of

Bb Dominant 9th (Bb dominant 9th) is built from the notes Bb, D, F, Ab, C, with the interval pattern 1, 3, 5, b7, 9. A common dominant 9th chord across many styles.

Stack 1, 3, 5, b7 and 9 on a root of B♭ and you get Bb, D, F, Ab and C. That interval recipe is what makes the chord a ninth chord — move the same shape to another root and the character travels with it, which is why C9 sounds like a transposed B♭9.

Dominant 9th: Funky, soulful; James Brown territory.

Spelling: the notes above are written the way a score would write them, not simplified to the nearest piano key. That is why this chord is spelled with B♭ rather than its enharmonic equivalent.

Keys that contain B♭9

All 5 notes sit inside the scale of 2 keys. The roman numeral marks the degree the chord is rooted on.

Major keys

E♭ Majorrooted on the V

Minor keys

C Minorrooted on the VII

Other chords on B♭

Same root, different colour.

B♭Bb Major B♭mBb Minor B♭dimBb Diminished B♭augBb Augmented B♭sus2Bb Suspended 2nd B♭sus4Bb Suspended 4th B♭5Bb Power Chord B♭6Bb Major 6th

The same ninth shape, moved

The identical interval recipe, built on other roots.

C9C Dominant 9th D9D Dominant 9th E9E Dominant 9th F9F Dominant 9th G9G Dominant 9th A9A Dominant 9th B9B Dominant 9th F♯9F# Dominant 9th

Questions people ask about Bb9

What notes are in the Bb9 chord?: Bb9 is made of Bb, D, F, Ab and C — the 1, 3, 5, b7 and 9 degrees of a ninth chord built on Bb.
What keys use the Bb9 chord?: Every note of Bb9 belongs to 2 keys: Eb Major (V), C Minor (VII). The roman numeral is the scale degree the chord is rooted on.
How do you play Bb9 on guitar and piano?: This page shows Bb9 on guitar, piano, ukulele and mandolin — 8 voicings in total. Each diagram links to the full instrument page with alternate shapes, audio and common mistakes.
Is Bb9 the same as A#9?: Yes. Bb9 and A#9 are enharmonic — identical pitches written two different ways. Which spelling you use depends on the key you are in; Bb9 is the spelling this site treats as canonical.

Learn the theory behind it

Why B♭9 behaves the way it does — the guides that explain the chord instead of just spelling it.

Barre Chords — The Wall Every Guitarist ClimbsThis one asks for a barre. The article is the fix for the buzzing and the aching hand.7 min read Functional Harmony: Three Roles, One EngineWhat a seventh chord is for — tension, resolution, and the seat it takes in the key.6 min read The 12-Bar Blues — Three Chords, A Century of HitsSeventh chords are the whole sound of the blues. Twelve bars is where to hear it.7 min read