Suspended Chords
10 chords in this group
A suspended chord replaces the third with the note next to it — a second or a fourth. Take the third away and the chord stops saying whether it is major or minor. That single missing note is the whole idea, and it is why sus chords sit under so many intros, riffs and open guitar parts.
sus2 and sus4
Csus4 is C, F and G: the third is replaced by a perfect fourth. Csus2 is C, D and G: replaced by a major second. Neither is major and neither is minor, because the note that decides that question is simply not there.
The two behave differently. A suspended fourth leans forward and traditionally falls to the third; a suspended second just opens the chord up and can sit still for bars. Same idea, opposite temperament.
The guitar shapes worth knowing
Dsus4 (xx0233) and Dsus2 (xx0230) come from the open D by adding or removing one finger, and that ease is why they are everywhere in acoustic music. Asus4 is x02230, Asus2 x02200, Esus4 022200, Csus4 x33011.
This is the practical answer to what people search for: you do not learn sus chords as a separate chart. You learn that lifting or adding one finger on a chord you already play turns it into one.
Suspension is older than the symbol
Classical harmony calls the same sound a suspension: a note held over from the previous chord that then steps down to the third. It is an event in voice leading rather than an object, and the fourth is expected to resolve.
Popular music turned the event into a chord with its own name. Both descriptions are of one sound — one explains why it works, the other tells you what to press.
Ten chords, one principle
The group runs from bare triads (sus2, sus4) up to C13sus4, which has six notes. What they share is the missing third, not the size. Add a minor seventh and you get C7sus4, the most common suspended chord in modern harmony; add a ninth and you get C9sus4, one barre at the third fret.
There is also sus24, which suspends in both directions at once, and susb9, a three-note frame with a lowered second that sets a Phrygian colour in the smallest possible statement.
When to reach for one
When the harmony must be present without committing: intros, pads under a spoken vocal, a long chord before the singer decides the mode. Also as delay — put a sus4 before its resolution and the arrival lands harder for costing one extra beat.
The one place to be careful is a dense mix. Without a third, a sus chord gives the ear less to hold on to, so a whole section of them can start to feel like a section with no harmony at all.
Frequently asked questions
What does sus mean in a chord?
Suspended: the third is replaced by a second or a fourth, so the chord is neither major nor minor.
What is the difference between sus2 and sus4?
sus2 uses the second, sus4 the fourth. The fourth leans towards resolution; the second stays open.
How do I play sus chords on guitar?
Add or lift one finger from a chord you already know: open D becomes Dsus4 at xx0233 and Dsus2 at xx0230.