Suspended 4th
sus4
0 - 5 - 7Root + perfect 4th + perfect 5th
About Suspended 4th
A suspended fourth chord is a three-note chord in which the third is replaced by the fourth — in C that is C, F and G, written Csus4. The fourth sits one semitone above the third it displaced, and the ear hears that displacement as a note held back, which is exactly what the name describes.
Notes and formula
The formula is 1 – 4 – 5, or 0 – 5 – 7 in semitones from the root. The perfect fifth stays and the third is gone, so the chord has no quality: Csus4 is neither major nor minor.
It is the same set of notes as a sus2 on its fourth degree — C–F–G read from F is F–G–C, an Fsus2 — but they do not sound alike. The bass note decides which of the three notes is heard as the tension, and over C it is unmistakably the F.
How to play it
On guitar Csus4 is x33011: an open C with the first string fretted and the third replaced. Dsus4 at xx0233 and Asus4 at x02230 are the everyday shapes, each a single added finger away from the open major chord, which is why the sound is native to strummed guitar.
On piano the chord is C–F–G. The F is the note to voice clearly; buried under the fifth it disappears, and the chord stops sounding suspended at all.
What it does
The classical use is literal suspension: the fourth is held over from the previous chord and falls to the third on the next beat. Csus4 to C, with F stepping down to E, is a cadence figure older than tonal harmony itself and still the standard way to end a hymn.
Popular music dropped the obligation. A sus4 can now stand on its own for a whole bar, and the tension is treated as a texture rather than a promise — though the ear still expects the fall, which is why a song that never delivers it sounds deliberately withheld.
Where you hear it
The dominant version, 7sus4, is the backbone of gospel and of a great deal of soul: sit on it, then release into the plain dominant. In rock the plain triad does the same job, and the opening of Pinball Wizard is the textbook case — the suspension is the riff.
Worship and folk guitar use it almost as punctuation, adding and lifting a finger inside a held chord to keep a long bar moving without changing the harmony.
Sus4, sus2 and the eleventh
Csus4 and Csus2 both remove the third and differ in what they put in its place — F against D. Both are quality-neutral, and the fourth is the more tense of the two because it is a semitone from the note it replaced while the second is a whole tone.
Add a seventh and the family grows: C7sus4 is the gospel chord, C9sus4 the same with a ninth, and C11 is that chord again under a different name. All of them exist because the fourth and the major third refuse to sound together.
Scales that contain it
Ionian, Mixolydian, Dorian and Aeolian all fit: the chord asks only for a natural fourth and a perfect fifth, and every mode except Lydian and Locrian supplies them.
Lydian is the exception worth knowing, because it raises the fourth — the very note the chord is built on. Over a sus4 chord a Lydian melody contradicts the harmony directly, which is unusual: most modal choices over most chords are matters of colour rather than error.
Frequently asked questions
What notes are in a Csus4 chord?
C, F and G. On guitar the open form is x33011.
Does a sus4 chord have to resolve?
In common-practice writing, yes — the fourth falls to the third. In popular music it does not, and a suspended chord can stand for a whole section. The ear still leans toward the resolution, which is what makes withholding it effective.
What is the difference between sus2 and sus4?
Which note replaces the third. Csus2 uses D, a whole tone above the root; Csus4 uses F, a semitone above the third it displaced. Both chords are neither major nor minor, and the sus4 is the tenser of the two.