C Suspended 4th Chord

Chord Tones: C Suspended 4th Chord

Symbol: sus4, sus — Formula: 1-4-5

DegreeNoteFrequency (A=440, Equal)
1 C4 261.626 Hz
4 F4 349.228 Hz
5 G4 391.995 Hz

Chord Notation

Notation TypeSymbol / Value
Lead Sheet SymbolCsus4
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 C4 F4 G4 C C Suspended 4th Chord
First Inversion F4 G4 C4 F C Suspended 4th Chord/F
Second Inversion G4 C4 F4 G C Suspended 4th Chord/G

Harmonic Function

The C sus4 chord commonly functions as the tonic (I) in C major/minor. 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. The C Suspended 4th Chord specifically contains 3 notes: C, F, G (formula: 1-4-5). On piano, C-rooted chords sit entirely on white keys in their basic triad form, making them the first chords most students learn. Pop, folk, and singer-songwriter music heavily use C-rooted chords because open-position guitar voicings and piano shapes are immediately accessible.

Common Progressions

The C 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 C 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
C4 261.626 Hz 260.740 Hz 261.626 Hz
F4 349.228 Hz 347.654 Hz 348.834 Hz
G4 391.995 Hz 391.111 Hz 392.438 Hz

Scales Containing the C Suspended 4th Chord

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