B♭ suspended 4th chord on bass (B♭sus4)

Also called or written B♭sus4, B♭sus or B♭ Suspended

B♭ suspended 4th contains B♭, E♭, and F. The 6th-fret shape is a stretch, but the inversion at the 1st fret uses a barre for a warmer voicing.

6frB♭FB♭E♭EADG
Positions on the neck1 of 3
Practice B♭ suspended 4th chord

How it is built

B♭RootE♭Perfect fourthFPerfect fifth

Formula 1, 4, 5

Inversions

How do you play a B♭ suspended 4th chord on bass?

B♭ suspended 4th is played at the 6th fret as 6 8 8 8: index finger on the E string at fret 6, middle finger on the A string at fret 8, ring finger on the D string at fret 8 and pinky finger on the G string at fret 8.

Full note and interval breakdown
StringFretFingerNote
4 (E)61B♭ (1)
3 (A)82F (5)
2 (D)83B♭ (1)
1 (G)84E♭ (4)

IntermediateThe three-fret stretch from the index on the 4th string to the pinky on the 1st string demands a wide hand span.

B♭sus4/F inversion · fret 1

B♭ suspended 4th is played at the 1st fret as 1 1 1 3: barre your index finger across fret 1 and pinky finger on the G string at fret 3.

Full note and interval breakdown
StringFretFingerNote
4 (E)11 (barre)F (5)
3 (A)11 (barre)B♭ (1)
2 (D)11 (barre)E♭ (4)
1 (G)34B♭ (1)

B♭sus4/F inversion · fret 13

B♭ suspended 4th is played at the 13th fret as 13 13 13 15: barre your index finger across fret 13 and pinky finger on the G string at fret 15.

Full note and interval breakdown
StringFretFingerNote
4 (E)131 (barre)F (5)
3 (A)131 (barre)B♭ (1)
2 (D)131 (barre)E♭ (4)
1 (G)154B♭ (1)

Why it sounds like that

B♭ suspended 4th is built from the formula 1, 4, 5 — the root B♭, the perfect fourth E♭, and the perfect fifth F. The fourth replaces the third, which removes the major or minor quality and leaves an open, unresolved sound. Compare it with B♭ major, where the third is D.

What goes wrong with B♭ suspended 4th?

  • Letting the pinky collapse and mute the 1st string.
  • Pressing the middle finger too flat and deadening the 2nd string.
  • Rushing the shift so the index lands short of the 6th fret.

When to use it

B♭ suspended 4th works as a suspended colour in B♭ major progressions like B♭–E♭–F–B♭, the I–IV–V–I, where it delays the resolution of B♭ major. It also fits rock, pop, and gospel when a chord needs to hover before landing.

Changing to and from B♭ suspended 4th

  • Move to B♭ major by lifting the middle finger and placing it on the 3rd string, 7th fret while keeping the index and ring in place.
  • Slide the shape down one fret to the 5th fret to reach A suspended 4th.

Which voicing to use

The 6th-fret shape puts B♭ in the bass for a rooted, stable sound. The B♭sus4/F inversion places F in the bass, which softens the chord and works well when the bass line is descending toward E♭.

Other B♭ chords

Common questions

How is B♭ suspended 4th written?

B♭ suspended 4th is written as B♭sus or B♭sus4. The ASCII spelling is Bb, so you may see Bbsus or Bbsus4. It is also spelled A♯ in enharmonic notation for the same sounding root.

What is the difference between B♭ suspended 4th and B♭ suspended 2nd?

B♭ suspended 4th replaces the third with the fourth, E♭. B♭ suspended 2nd replaces the third with the second, C, creating an even more open sound.

Can B♭ suspended 4th resolve to B♭ minor?

Yes, B♭ suspended 4th can resolve to B♭ minor by moving the fourth down a half step to the minor third, D♭. This resolution is common in classical and folk music.