What Are sus2 and sus4 Chords?

Most simple chords have a third. The third is what helps the ear understand whether a chord is major or minor.

For example:

C  = C–E–G
Cm = C–E♭–G

The C major chord has a major third: E. The C minor chord has a minor third: E♭.

Sus chords have no third. Instead, they use the second or fourth degree:

Csus2 = C–D–G
Csus4 = C–F–G

Because of this, sus chords do not sound clearly major or clearly minor. They feel suspended, as if they are waiting for what comes next.

Simple definition

A sus chord is a chord where the third is replaced by the second or fourth degree.

There are two main types:

sus2 = 1–2–5
sus4 = 1–4–5

For example, from C:

Csus2 = C–D–G
Csus4 = C–F–G

Compare this with a regular C major chord:

C = C–E–G

C contains E, the third. In Csus2 and Csus4, E is replaced by another degree.

The main idea: a sus chord removes the third, so it temporarily removes the clear major or minor color.

What sus means

sus is short for suspended.

Historically, this is connected with suspension: one note is held over before resolving into a regular chord tone.

For example, in Csus4, the note F often resolves to E:

Csus4 → C
F     → E

That is why Csus4 often sounds as if it wants to become a regular C chord.

But in modern music, sus chords do not always have to resolve. They can also be used as a color on their own.

Formulas for sus2 and sus4

Let’s compare three chords from C.

The formula is more useful than the fingering. On guitar, one sus chord can have several shapes, but the interval idea stays the same.

Why sus chords do not sound major or minor

Major and minor are defined by the third.

C major = C–E–G
C minor = C–E♭–G

E gives the chord a major character. E♭ gives it a minor character.

Csus2 has no third:

Csus2 = C–D–G

Csus4 also has no third:

Csus4 = C–F–G

The ear does not receive the main signal: “this is major” or “this is minor”. The sound becomes open, neutral, and slightly unfinished.

That is why sus chords work well in rock, pop, folk, ambient music, and soundtracks. They add motion and color without locking the mood too firmly.

Csus2

Csus2 is built with this formula:

1–2–5

From C, that gives:

C–D–G

In Csus2, the third E is replaced by the second degree, D.

Because of this, the chord sounds open and soft. It has less tension than sus4. It often feels like a light expansion of the regular chord, but without a clear major color.

Compare:

C     = C–E–G
Csus2 = C–D–G

C contains E, so it sounds clearly major. Csus2 uses D instead of E, so the sound becomes more neutral.

Csus4

Csus4 is built with this formula:

1–4–5

From C, that gives:

C–F–G

In Csus4, the third E is replaced by the fourth degree, F.

Csus4 sounds more tense than Csus2. The reason is that F sits close to E and often wants to resolve downward:

F → E

The movement:

Csus4 → C

sounds natural and complete. This is one of the most recognizable sus4 effects: first suspension, then a return to the regular chord.

sus2 and sus4: what is the difference?

Both chords remove the third, but they do it differently.

Compare them from C:

Csus2 = C–D–G
Csus4 = C–F–G

Csus2 often sounds calmer. Csus4 more often creates a feeling of expectation.

But this is not a strict rule. In real music, the effect depends on tempo, rhythm, register, instrument, and the surrounding chords.

Sus chord and add chord: what is the difference?

This is one of the most common points of confusion.

A sus chord replaces the third.

An add chord adds a new degree but keeps the third.

Compare:

Csus2 = C–D–G
Cadd9 = C–E–G–D

Csus2 has no E, so it has no third.

Cadd9 contains both E and D. So it is not a sus chord. It is a C major chord with an added ninth.

The same idea applies to sus4 and add11:

Csus4  = C–F–G
Cadd11 = C–E–G–F

Csus4 has no E. Cadd11 keeps E.

In short:

sus = the third is removed and replaced
add = the third stays, and another degree is added

This is a big difference by ear. Cadd9 still sounds like C major. Csus2 sounds more open and less defined.

Sus chords and seventh chords

Sus can also combine with seventh chords.

For example:

C7sus4

This means: take C7, but use the fourth degree instead of the third.

Regular C7:

C7 = C–E–G–B♭

C7sus4:

C7sus4 = C–F–G–B♭

C7 contains E, the major third. C7sus4 uses F instead of E.

This chord is often used before a dominant chord or a tonic:

C7sus4 → C7 → F

First we hear the suspension, then the third appears, and then the chord resolves further.

How sus chords work in progressions

Sus chords often appear next to regular chords.

For example:

C → Csus4 → C
C → Csus2 → C

These movements create small motion inside one harmonic area. The harmony stays close to the same chord, but something comes alive inside it.

Another example:

G → Gsus4 → G

In songs, this can sound like a small tension before returning to the regular chord.

Why sus chords are comfortable on guitar

On guitar, sus chords often fall naturally under the fingers.

For example, in open-position shapes, you can move quickly between:

D → Dsus2 → Dsus4 → D
A → Asus2 → Asus4 → A
E → Esus2 → Esus4 → E

These movements are common in accompaniment. They make a simple strumming pattern more alive and add melodic motion inside the chord.

The point is not just to memorize the shape. It is better to understand which degree is changing:

3 → 4 → 3

or:

3 → 2 → 3

Then the shape stops being random.

How to see sus chords on the fretboard

To understand a sus chord on the fretboard, find three things:

1 = root
2 or 4 = replacement for the third
5 = fifth

For Csus2:

C = 1
D = 2
G = 5

For Csus4:

C = 1
F = 4
G = 5

The main question is: where is the third of the regular chord, and what replaced it?

For example, in C:

E = 3

In Csus4, F is used instead of E:

F = 4

In Csus2, D is used instead of E:

D = 2

When you see the intervals, a sus chord stops being a strange separate shape. It becomes a simple replacement of the third.

How Six Strings App can help

In Chords, Arpeggios, Scales, you can compare C, Csus2, Csus4, Cadd9, and C7sus4. Turn on interval view to see where the third is, and where it is replaced by the second or fourth degree.

In the Fretboard Explorer, you can find the notes of a sus chord across the whole fretboard and build your own shapes in different positions.

In the Song Builder, you can replace a regular chord with sus2 or sus4 and hear how the character of the progression changes.

In Harmony, you can check how sus chords work next to diatonic chords and dominants.

5-minute exercise

Take C and play three versions:

C
Csus2
Csus4

Then play the resolutions:

Csus4 → C
Csus2 → C

Listen not to the shape, but to the feeling:

C     = stable
Csus2 = open
Csus4 = suspended

The main goal is to hear how the absence of the third changes the character of the chord.

Guitar exercise

1. Take a simple open D chord.
2. Find Dsus4.
3. Play D → Dsus4 → D.
4. Then find Dsus2.
5. Play D → Dsus2 → D.
6. Repeat the same idea with A and E.
7. Pay attention to which degree replaces the third.

D     = D–F♯–A
Dsus2 = D–E–A
Dsus4 = D–G–A

This connects the fingering with the theory, instead of turning it into a memorized shape.

Progression exercise

Play a simple progression:

C → G → Am → F

Then replace some chords with sus versions:

C → Gsus4 → G → Am → F
C → Csus2 → G → Am → F

Compare where the sus chord sounds like an embellishment and where it sounds like a separate color.

Common mistakes

Thinking that sus2 is a major chord with an added second degree. No. Sus2 has no third. If the third stays, the chord is already add9 or another extended chord.

Thinking that sus4 is a major chord with an added fourth degree. In sus4, the third is replaced by the fourth degree. If the third stays, it is not a regular sus4.

Ignoring the third. The whole idea of a sus chord is that there is no third. That is why the chord does not sound clearly major or minor.

Always resolving sus4 into a regular chord. You can do that, but you do not have to. In modern music, a sus chord can work as a color on its own.

Memorizing only the fingering. A shape is useful, but it is more important to understand which degree replaces the third: the second or the fourth.

Confusing sus2 and add9. Csus2 = C–D–G. Cadd9 = C–E–G–D. In add9, the third remains.

What to study next

• What Is a Chord in Music — the basic idea of a chord.
• How Triads Are Built — root, third, and fifth.
• Major Triad — the 1–3–5 formula.
• Minor Triad — the 1–♭3–5 formula.
• What Is a Seventh Chord — four-note chords.
• Main Types of Seventh Chords — maj7, 7, m7, m7♭5, and dim7.
• Chords, Arpeggios, Scales — a tool where you can compare sus2, sus4, and add chords on the fretboard.

Short summary

Sus2 and sus4 are chords without a third. In sus2, the third is replaced by the second degree. In sus4, it is replaced by the fourth degree. That is why these chords do not sound clearly major or minor. They create an open, suspended sound and help bring simple progressions to life. The main thing is not to confuse sus with add: in sus chords, the third is replaced; in add chords, the third remains.