semicord

Bbsus4 Bb suspended fourth chord

Notes
Bb Eb F
Formula
1 4 5
Semitones
0 5 7 above the root
Also written
A#sus4 (A# D# E#)
Other symbols
Bbsus

Bb to Eb is a perfect fourth (5 semitones), Eb to F is a major second (2 semitones). The third is replaced by the fourth (Eb), which wants to fall to the third. With Eb in the bass the same three keys read as Ebsus2.

Bbsus4 on the piano

C4D4E4F4G4A4B4C5D5E5F5G5A5B5C#4Eb4F#4Ab4Bb4C#5Eb5F#5Ab5Bb5C4BbC5EbF

Root position from Bb4: Bb4, Eb5, F5. Middle C is C4.

Bbsus4 on the guitar

Standard tuning (E A D G B E). Strings run low E on the left to high e on the right, frets downwards; × is a muted string, ○ an open string, and each dot shows the note it sounds, with the root in blue-green. Every shape below has Bb as its lowest note.

×BbBbFFBbBbEbEbFF
A-shape barre, root on the A string at fret 1
x 1 3 3 4 1 (low E to high e)
Sounds Bb2 F3 Bb3 Eb4 F4
6frBbBbFFBbBbEbEbFFBbBb
E-shape barre, root on the E string at fret 6
6 8 8 8 6 6 (low E to high e)
Sounds Bb2 F3 Bb3 Eb4 F4 Bb4

The barre shapes are movable: an E-shape chord's root is the note under your first finger on the low E string, an A-shape chord's root is the note on the A string. Slide the same grip up or down to play suspended fourth chords on other roots.

Inversions of Bbsus4

An inversion puts a note other than the root in the bass. The name is what semicord's chord finder calls those notes played bottom to top; a slash name like C/E means a C chord with E in the bass.

PositionNotes, bass firstNamedListen
Root positionBb Eb FBbsus4
1st inversionEb F BbEbsus2 (also read as Bbsus4/Eb)
2nd inversionF Bb EbF7sus4 (also read as Bbsus4/F)

Where Bbsus4 fits

A sus chord has no third, so it is neither major nor minor and has no fixed place in a key. Bbsus4 usually resolves to Bb or Bbm: the fourth, Eb, falls a half or whole step to the third. Its most common job is Vsus4 in Eb major, delaying the V chord: Bbsus4 → Bb → Eb.