Absus4

Q: What notes are in the Absus4 chord?

The Absus4 chord (Ab Sus4) contains: Ab, Db, Eb. Its interval structure is shown above in the Theory section.

Q: How do I build Absus4 on the keyboard?

Take the root and add the remaining chord tones following the interval formula. The highlight shows chord content, while the inversion control changes which chord tone is in the bass.

Q: Which keys is Absus4 found in?

The chord acts as a diatonic degree in several keys — they are marked on the circle of fifths in the "Harmonic context" block.

Q: What can I substitute for Absus4?

A substitution depends on harmonic function and voice leading, not only on shared tones. Computed options appear in the "Substitutions" block and should be checked in context.

Ab Sus4

Octaves

Musical context

ChordAbsus4Ab Sus4

ArpeggioAb majorBroken triad

ScaleAb major7 notes

KeyAb majorMajor key

ProgressionPop axisSequence

How the chord relates to the scale, mode, key and progression.

Theory

General info

Full name: Ab Sus4
Symbol: Absus4
Root: Ab
Quality: Sus4

Chord notes

1Abroot

4Dbperfect 4th

5Ebperfect 5th

Functions & resolutions

Typical function in key: VDominant (V)C# major
Stability / tension: Moderate tension — suspension awaits resolution
Most common resolutions: AbAb Major AbmAb Minor
Unstable degrees: 3C
4Db
resolves down to the 3rd
Main resolution: Absus4source
AbAb Major
The suspended 4th in Absus4 pulls down to the 3rd, resolving to Ab major or minor.
Other resolutions: Absus4source
Deceptive resolution
AbmAb Minor
Absus4 can resolve to minor instead of major — the 4th drops to the minor 3rd.
Absus4source
No resolution needed
In modal music, a sus chord may remain an independent sonority without 4–3 or 2–3 motion; with no 3rd, it defines neither major nor minor quality.
Absus4source
Jazz reharmonization
Ab7sus4Ab 7sus4
In jazz, 7sus4 may retain its dominant bass and minor 7th without immediately resolving the 4th to the 3rd; it may also move to another sus chord.
Absus4source
Functional resolution
DbDb Major
A sus chord can move up a 4th or down a step, functioning as a suspension from degrees other than the tonic.

Features

Character: No 3rd, with 4th-degree tension
Characteristic interval: Fourth instead of 3rd (4)
Description: The 4th replaces the 3rd, so the chord defines neither major nor minor quality. In a typical sus4 resolution, the 4th descends to the 3rd.
Application: Pop and rock (sus4 → major)
Pause before resolution
Building tension

Voicing & structure

Root position

v1Ab(Ab4)Bass

root

v2Db(Db5)P4from Ab

v3Eb(Eb5)M2from Db

Harmony

Compatible scales

All chord tones are contained in these scales — use them for improvisation.

ScaleC# Major pentatonic ScaleC# Yo (Japanese)ScaleC# Akebono (Japanese)ScaleC# Hirajoshi (Japanese)ScaleD# Minor pentatonic ScaleD# Iwato (Japanese)ScaleG# Minor pentatonic ScaleG# In (Japanese)ScaleG# Yo (Japanese)ScaleF# Major pentatonic

This chord on guitar 🎸

See how Absus4 looks on guitar.

Explore

Circle of fifths

Highlighted major keys contain this chord among their diatonic harmonies.

Relative key: FmF minor
Dominant: EbEb major
Subdominant: DbDb major
Key signature: 4 flats (Bb, Eb, Ab, Db)

What to learn next

ScaleAb Ionian (major)Scale to improvise over this chord ChordAb MajorA nearby chord on the same root — compare the sound PracticeChord trainerLock the fingering into muscle memory ProgressionChord progressionsHow this chord works inside real progressions ChordAb Sus2Another related chord to practise

Recommended for you

Ab MajorA chord that sounds close

Ab Sus2A chord that sounds close

Ab 7sus4A chord that sounds close

Ab Ionian (major)A scale related to this chord

Ab DorianA scale related to this chord

Practice

Keyboard Trainer

Reinforce it in practice — play and name notes on the interactive keyboard.

Open Trainer

Test yourself

(Press any key to start)

What notes are in the Absus4 chord?

How do I build Absus4 on the keyboard?

Which keys is Absus4 found in?

What can I substitute for Absus4?