About Absus4 — triad voicings
Absus4 is Ab, Db and Eb — Ab 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.
Absus4 notes and formula
| Ab | Db | Eb |
|---|---|---|
| 1 | 4 | 5 |
Suspended — classically it resolves down onto the third.
Also written Absus or Ab suspended 4th. The same chord either way; which spelling you meet depends on who wrote the chart.
How to play Absus4
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.
Absus4 has 46 of them, on the high-middle three, the top three strings, the top four strings, the bottom four strings, the middle four strings, the low-middle three, the bottom three strings, strings 6-4-3-2 and strings 5-3-2-1, from open position up to the 13th — every inversion the chord has: Ab in the bass, Db in the bass and Eb in the bass. The one to learn first is the Eb shape at the nut, which is the easiest grip here.
6 of them sit on the top 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 xx1124 — no barre and down at the nut. None of the shapes for Absus4 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 14th.
| Frets | Where | Bass | Top | Hand |
|---|---|---|---|---|
| 4x1124 | 1st fret | Ab, root position | Ab | all fretted |
| xx1124 | 1st fret | Eb, 2nd inversion | Ab | all fretted |
| 466644 | 4th fret | Ab, root position | Ab | barred |
| xx6899 | 6th fret | Ab, root position | Db | all fretted |
| x-11-11-8-9-x | 8th fret | Ab, root position | Ab | all fretted |
| x-11-13-13-14-11 | 11th fret | Ab, root position | Eb | all fretted |
How to use Absus4
Voice by voice, Absus4 → Ab. One voice moves by a semitone, and 2 notes are common to both chords.
| In Absus4 | Moves | In Ab |
|---|---|---|
| Ab, the root | stays where it is | Ab, the root |
| Db, the fourth | falls a semitone | C, the major third |
| Eb, the fifth | stays where it is | Eb, the fifth |
In which keys. Every note of Absus4 belongs to C# major (the V), C# minor (the v), Eb minor (the iv), E major (the iii), F minor (the ♭III), F# major (the ii), Ab major (the I), Ab minor (the i), Bb minor (the ♭VII) and B major (the vi).
What to play over Absus4
Every note of Absus4 is in Ab minor pentatonic, Ab blues, Ab major, Ab mixolydian and Ab dorian.
Chords near Absus4
Change one note of Absus4 and you have Ab (the fourth becomes a major third), Abm (the fourth becomes a minor third), Absus2 (the fourth becomes a ninth), Ab5 (drop the fourth) or Ab7sus4 (add the flat seventh).
Absus4 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 Absus4’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.