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Chord & Fret

Bb9 — dominant ninth

Also written A#9 — the same chord, spelled the other way.

Notes in Bb9: Bb – D – F – Ab – CFormula: 1 – 3 – 5 – b7 – 9

In the formula, the numbers count steps of the major scale starting from the note that names the chord; "b" lowers a half step, "#" raises one — and a slash names the bass note.

The 9 is the dominant chord with the ninth. It keeps the dominant function and adds color and breadth.

The same chord on all four instruments

Bb9, x 1 0 1 1 1Bb91234×BbDAbCF
Guitar
Bb9, x 1 0 1 1 1Bb91234×BbDAbCF
Electric guitar
Bb9, 8 7 9 10Bb972134BbDAbC
Cavaquinho
Bb9, 3 0 4 5Bb9123BbCAbD
Ukulele

Where to use it: Blues, funk, choro and broader dominants.

Every region of the neck hides more shapes of Bb9. In Chord & Fret, you hear every shape strummed string by string, in each instrument's own voice; open every variation on the neck, grouped by bass note; and change the tuning — the shape rewrites itself. Start free. Unlock everything with Pro. Plays offline.

See the whole neck in Chord & Fret →

Part of the Extended family.

Other chords in this family

Bbmaj9A#m9A#m11Bb13Bbmaj9(#11)Bb11Bbmaj11Bbmaj13Bbm13Bbm(maj9)

See all chord types and qualities →