B♭ Dominant Ninth Chord

Chord Tones: B♭ Dominant Ninth Chord

Symbol: 9 — Formula: 1-3-5-♭7-9

Chord Notation

Roman numeral (e.g. I, IV, V) and Nashville Number notation are key-dependent. See Keys pages for chord function within specific keys.

Inversions

Harmonic Function

The B♭ dominant ninth chord commonly functions as the subtonic (♭VII) in C major or subdominant in F major. Its harmonic role varies by key — in major keys it provides stable harmonic grounding.

The dominant ninth chord extends the dominant seventh with a ninth, adding color and richness to one of music's most harmonically active chords. Essential in jazz, blues, and funk. The B♭ Dominant Ninth Chord specifically contains 5 notes: B♭, D, F, A♭, C (formula: 1-3-5-♭7-9). On piano, Bb-rooted chords start on a black key and create hand shapes that jazz pianists find ideal for voicing seventh chords and extended harmonies. Jazz standards, swing, and big band charts are heavily weighted toward Bb because it allows horn sections to play in their most comfortable range.

Common Progressions

The B♭ Dominant Ninth Chord frequently appears in these progression patterns (shown in Roman numeral notation relative to key):

• V9-I
• ii7-V9-I

Songs Featuring the Dominant Ninth Chord

Well-known songs where the B♭ Dominant Ninth Chord — or this chord type — plays a prominent role:

• Purple Haze – Jimi Hendrix
• What's Going On – Marvin Gaye
• Superstition – Stevie Wonder

Tuning Frequencies Across Temperaments

Frequencies shown at A=440 Hz. View full temperament data for any note.

Scales Containing the B♭ Dominant Ninth Chord

These scales include the B♭ Dominant Ninth Chord as a diatonic or characteristic chord: