Bb7sus4

General info

Full name

Bb 7sus4

Symbol

Bb7sus4

Root

Bb

Quality

7sus4

Chord notes

Functions & resolutions

Typical function in key

viRelative tonic (vi)C# major

Stability / tension

High tension — requires resolution

Most common resolutions

EbEb MajorCmC Minor

Unstable degrees

3D

4Eb

resolves down to the 3rd

6G

b7Ab

resolves down to the tonic 3rd

Main resolution

Bb7sus4source

EbEb Major

Dominant 7th Bb7 naturally resolves up a 4th to Eb. It is the tritone between the chord's 3rd and 7th that creates this pull.

Other resolutions

Bb7sus4source

Deceptive resolution

CmC Minor

Instead of the tonic, the dominant resolves to the vi degree. Creates surprise and is often used to extend a musical phrase.

Bb7sus4source

Modal resolution

AbAb Major

In rock and blues, the dominant often moves to bVII or IV instead of the tonic, creating a modal flavor.

Bb7sus4source

Jazz reharmonization

E7E Dominant 7

Tritone substitution: Bb7 can be replaced by E7 (a tritone away). Both chords share the same tritone between the 3rd and 7th, resolving to the same tonic.

Bb7sus4source

Functional resolution

Bbsus4Bb Sus4

The dominant can resolve beyond the tonic: moving to IV (subdominant) or to a suspension (sus4) are common alternatives in pop and folk music.

Features

Character

Dominant, with no 3rd and a 4th

Characteristic interval

Fourth (4), Minor 7th (b7)

Description

The 4th replaces the 3rd, so major quality is withheld, while the minor 7th preserves dominant colour. The 4th often descends to the 3rd of a dominant seventh chord.

Application

• 4–3 suspension over dominant
• Modal harmony
• Funk and jazz

Voicing & structure

Harmony

Compatible scales

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