F Suspended 4th Chord

Chord Tones: F Suspended 4th Chord

Symbol: sus4, sus — Formula: 1-4-5

DegreeNoteFrequency (A=440, Equal)
1 F 349.228 Hz
4 Bb 466.164 Hz
5 C 261.626 Hz

Chord Notation

Notation TypeSymbol / Value
Lead Sheet SymbolFsus4
All Common Symbolssus4, sus
Interval Formula1-4-5
Harmonic Categoryopen

Roman numeral (e.g. I, IV, V) and Nashville Number notation are key-dependent. See Keys pages for chord function within specific keys.

Inversions

InversionNotes (low to high)Bass NoteSlash Notation
Root Position F Bb C F F Suspended 4th Chord
First Inversion Bb C F Bb F Suspended 4th Chord/Bb
Second Inversion C F Bb C F Suspended 4th Chord/C

Harmonic Function

The F sus4 chord commonly functions as the subdominant (IV) in C major — plagal cadence endpoint. Its harmonic role varies by key — in major keys it provides stable harmonic grounding.

The sus4 chord replaces the third with a perfect fourth, creating tension that traditionally resolves down to the major third. It creates anticipation and is common before dominant chords.

Common Progressions

The F Suspended 4th Chord frequently appears in these progression patterns (shown in Roman numeral notation relative to key):

Songs Featuring the Suspended 4th Chord

Well-known songs where the F Suspended 4th Chord — or this chord type — plays a prominent role:

Tuning Frequencies Across Temperaments

Frequencies shown at A=440 Hz. View full temperament data for any note.

NoteEqual Temp.PythagoreanJust Intonation
F 349.228 Hz 347.654 Hz 348.834 Hz
Bb 466.164 Hz 463.538 Hz 470.926 Hz
C 261.626 Hz 260.740 Hz 261.626 Hz

Scales Containing the F Suspended 4th Chord

These scales include the F Suspended 4th Chord as a diatonic or characteristic chord: