Dominant 9th sus4
9sus4
0 - 5 - 7 - 10 - 147sus4 + major 9th
About Dominant 9th sus4
A dominant ninth sus4 chord is a suspended dominant with a ninth added — in C that is C, F, G, B♭ and D, written C9sus4. It is the chord gospel and soul players sit on before a resolution, and it has three names in common use because three different traditions arrived at the same five notes from different directions.
Notes and formula
The formula is 1 – 4 – 5 – ♭7 – 9, or 0 – 5 – 7 – 10 – 14 in semitones. A dominant with no third, a fourth in its place, and a ninth above.
The absence of the third is what makes the chord restful. With no E there is no tritone against the B♭, so nothing forces a resolution and the chord can be held as long as the arrangement wants.
Three symbols, one sound
Written from the root it is C9sus4. Written as a slash chord it is Gm7/C, and that is how most arrangers notate it, because a G minor seventh over a C bass is easier to read and to voice.
Written as a stacked chord it is C11 — the eleventh chord with its clashing third already dropped. Which of the three appears on a chart says more about the idiom than about the music, and a player who knows all three saves time reading anything.
The practical consequence: if a chart says C11 and another says Gm7/C, they are asking for the same thing.
How to play it
On guitar the classic form is x33333 — one finger barred across the fifth strings at the third fret, sounding C–F–B♭–D–G. It is the easiest five-note chord on the instrument.
On piano the reliable voicing is C in the left hand and a plain G minor seventh in the right. Nothing else is needed, and adding the missing E would undo the chord.
What it does
A dominant ninth with a suspended fourth delays. The standard gospel move is C9sus4 to C7 to F: the fourth falls to the third, the tritone appears at the last moment, and the resolution lands harder for having waited.
It also stands alone. A verse built on this chord sounds neither major nor minor and never grows impatient, which is why it underpins so much seventies soul and so many modern worship songs.
Against 7sus4 and 13sus4
C7sus4 is the same chord without the ninth: four notes, a little plainer. C13sus4 adds a thirteenth on top and is the fullest member of the family.
All three behave identically. The choice is texture — how much of the band is already playing, and how much room the voicing has.
Scales that contain it
Mixolydian fits and is the default. Because the chord has no third, a soloist may play a minor third against it without a clash, which widens the choice to the minor pentatonic and the blues scale.
Thinking in terms of the underlying G minor seventh is faster: Dorian on G covers every note of the chord and every note usually played over it.
Frequently asked questions
What notes are in a C9sus4 chord?
C, F, G, B♭ and D. On guitar it is x33333, one barred finger at the third fret.
Is C9sus4 the same as C11?
Yes as played. C11 in theory also contains a third, but the third is always dropped because it clashes with the eleventh — and what is left is exactly this chord.
Why write Gm7/C instead?
Because it is easier to read and to voice. Arrangers write the upper structure as a familiar chord and put the real root underneath it.