About Bbsus4 — triad voicings
Bbsus4 is Bb, Eb and F — Bb with the third replaced by the fourth.
It sounds suspended mid-air. Played before the plain chord it is the oldest tension-and-release move there is.
Bbsus4 notes and formula
| Bb | Eb | F |
|---|---|---|
| 1 | 4 | 5 |
Suspended — classically it resolves down onto the third.
Also written Bbsus or Bb suspended 4th. The same chord either way; which spelling you meet depends on who wrote the chart.
How to play Bbsus4
Three notes on one string set. No seventh, so nothing is claimed about the chord beyond its quality.
Thin on their own, excellent over a bass line or against someone else’s harmony.
Bbsus4 has 47 of them, on the bottom three strings, the bottom four strings, the high-middle three, the top three strings, the top four strings, the middle four strings, the low-middle three, strings 5-3-2-1 and strings 6-4-3-2, from open position up to the 13th — every inversion the chord has: Bb in the bass, Eb in the bass and F in the bass. The one to learn first is the F shape at the nut, which is the easiest grip here.
6 of them sit on the bottom four strings, so you can run the inversions up one set without changing strings — which is the whole reason to learn them as a family rather than as separate grips.
Start with xx3346 — no barre and low, at the 3rd fret. None of the shapes for Bbsus4 uses an open string, so every one of them is movable; the lowest sits at the 1st fret. 1 of the 6 needs a barre. Together they cover the neck from the 1st fret to the 13th.
| Frets | Where | Bass | Top | Hand |
|---|---|---|---|---|
| x13341 | 1st fret | Bb, root position | F | all fretted |
| 6x3346 | 3rd fret | Bb, root position | Bb | all fretted |
| xx3346 | 3rd fret | F, 2nd inversion | Bb | all fretted |
| 688866 | 6th fret | Bb, root position | Bb | barred |
| x-x-8-10-11-11 | 8th fret | Bb, root position | Eb | all fretted |
| x-13-13-10-11-x | 10th fret | Bb, root position | Bb | all fretted |
How to use Bbsus4
Voice by voice, Bbsus4 → Bb. One voice moves by a semitone, and 2 notes are common to both chords.
| In Bbsus4 | Moves | In Bb |
|---|---|---|
| Bb, the root | stays where it is | Bb, the root |
| Eb, the fourth | falls a semitone | D, the major third |
| F, the fifth | stays where it is | F, the fifth |
In which keys. Every note of Bbsus4 belongs to C minor (the ♭VII), C# major (the vi), Eb major (the V), Eb minor (the v), F minor (the iv), F# major (the iii), G minor (the ♭III), Ab major (the ii), Bb major (the I) and Bb minor (the i).
What to play over Bbsus4
Every note of Bbsus4 is in Bb minor pentatonic, Bb blues, Bb major, Bb mixolydian and Bb dorian.
Chords near Bbsus4
Change one note of Bbsus4 and you have Bb (the fourth becomes a major third), Bbm (the fourth becomes a minor third), Bbsus2 (the fourth becomes a ninth), Bbsus2sus4 (add the ninth), Bb5 (drop the fourth) or Bb7sus4 (add the flat seventh).
Bbsus4 is a suspended chord — root and fifth, with a second or fourth where the third would be — or nothing at all. Suspended and power chords on every root.
On Bbsus4’s sound and use this page follows Edward Aldwell & Carl Schachter, Harmony and Voice Leading (Schirmer / Cengage, 4th ed., 2011). The shapes and the derived voicings come from different places, and both are explained in where the chords and the theory come from.