B♭ 9th chord on guitar (B♭9)

Also called or written B♭9 or B♭

B♭ 9th is built from B♭, D, F, A♭ and C. This open position shape is advanced because it requires a clean mute on the low E string.

B♭DA♭CFEADGBE
Positions on the neck1 of 5
Practice B♭ 9th chord

How it is built

B♭RootDMajor thirdFPerfect fifthA♭Minor seventhCNinth

Formula 1, 3, 5, ♭7, 9

Inversions
  • Root positionB♭–D–F–A♭–CB♭9×-1-0-1-1-1
  • First inversionD–F–A♭–C–B♭B♭9/D×-5-6-5-6-6
  • Second inversionF–A♭–C–B♭–DB♭9/F1-1-0-1-1-×
  • Third inversionA♭–C–B♭–D–FB♭9/A♭4-3-3-3-3-4
  • Fourth inversionC–B♭–D–F–A♭B♭9/C×-3-3-3-3-4

How do you play a B♭ 9th chord on guitar?

B♭ 9th is played in open position as × 1 0 1 1 1: index finger on the A string at fret 1, middle finger on the G string at fret 1, ring finger on the B string at fret 1 and pinky finger on the high e string at fret 1. The D string rings open. The low E string stays muted.

Full note and interval breakdown
StringFretFingerNote
6 (E)muted
5 (A)11B♭ (1)
4 (D)openD (3)
3 (G)12A♭ (♭7)
2 (B)13C (2)
1 (e)14F (5)

AdvancedThe open position requires muting the low E string while fretting four notes with separate fingers, which can cause accidental string noise.

5th fret

B♭ 9th is played at the 5th fret as 6 5 6 5 6 ×: barre your index finger across fret 5, middle finger on the low E string at fret 6, ring finger on the D string at fret 6 and pinky finger on the B string at fret 6. The high e string stays muted.

Full note and interval breakdown
StringFretFingerNote
6 (E)62B♭ (1)
5 (A)51 (barre)D (3)
4 (D)63A♭ (♭7)
3 (G)51 (barre)C (2)
2 (B)64F (5)
1 (e)muted

6th fret

B♭ 9th is played at the 6th fret as 6 8 6 7 6 8: barre your index finger across fret 6, ring finger on the A string at fret 8, middle finger on the G string at fret 7 and pinky finger on the high e string at fret 8.

Full note and interval breakdown
StringFretFingerNote
6 (E)61 (barre)B♭ (1)
5 (A)83F (5)
4 (D)61 (barre)A♭ (♭7)
3 (G)72D (3)
2 (B)61 (barre)F (5)
1 (e)84C (2)

B♭9/D inversion · fret 5

B♭ 9th is played at the 5th fret as × 5 6 5 6 6: barre your index finger across fret 5, middle finger on the D string at fret 6, ring finger on the B string at fret 6 and pinky finger on the high e string at fret 6. The low E string stays muted.

Full note and interval breakdown
StringFretFingerNote
6 (E)muted
5 (A)51 (barre)D (3)
4 (D)62A♭ (♭7)
3 (G)51 (barre)C (2)
2 (B)63F (5)
1 (e)64B♭ (1)

B♭9/D inversion · fret 8

B♭ 9th is played at the 8th fret as 10 8 8 10 9 8: barre your index finger across fret 8, ring finger on the low E string at fret 10, pinky finger on the G string at fret 10 and middle finger on the B string at fret 9.

Full note and interval breakdown
StringFretFingerNote
6 (E)103D (3)
5 (A)81 (barre)F (5)
4 (D)81 (barre)B♭ (1)
3 (G)104F (5)
2 (B)92A♭ (♭7)
1 (e)81 (barre)C (2)

Why it sounds like that

B♭ 9th combines a B♭ major triad (1, 3, 5) with a minor seventh and a major ninth: 1, 3, 5, ♭7, 9. The added ninth C creates a jazzy tension against the ♭7 A♭. Compare it with B♭ 7th, which lacks the ninth.

What goes wrong with B♭ 9th?

  • Letting the low E string ring open, adding an E that is not in the chord.
  • Flattening the index finger so it touches the open D string and deadens it.
  • Not pressing the pinky firmly on the high e string, causing a buzz at fret 1.

When to use it

B♭ 9th functions as the dominant in E♭ major, appearing in progressions like E♭–A♭–B♭–E♭ (I–IV–V–I). It fits jazz, funk and R&B grooves. Compare it with B♭ major to hear how the seventh and ninth add tension.

Changing to and from B♭ 9th

  • Move to B♭ major by lifting the pinky and ring finger to leave the high e string open.

Which voicing to use

The open position voicing is the most practical, with B♭ in the bass. Higher fret voicings at the 5th and 6th frets offer a brighter, more compact sound for ensemble playing.

Other B♭ chords

Common questions

How is B♭ 9th written?

B♭ 9th is written as B♭9 or Bb9. The symbol B♭9 always means a dominant ninth chord with a minor seventh and a major ninth. It is also spelled A♯ in enharmonic notation for the same sounding root.

What is the difference between B♭ 9th and B♭ add 9?

B♭ 9th includes the minor seventh A♭, while B♭ add 9 is a B♭ major triad with the ninth C added and no seventh. The add 9 sounds more consonant and less bluesy.

Why is the low E string muted in the open position?

B♭ remains a supplied chord tone; mute it only to preserve the displayed bass order. Letting it ring would add an unwanted note that clashes with the harmony.