Sus Chords on Guitar - Sus2 and Sus4

Sus2 and sus4: the formula

A major chord is root, 3rd and 5th (1 3 5). A sus chord keeps the root and the 5th and swaps the 3rd:

• sus2 = 1 2 5. The 3rd drops a whole step to the 2nd.
• sus4 = 1 4 5. The 3rd rises a half step to the 4th.

Because the 3rd is what makes a chord major or minor, the same sus chord fits both. Asus4 can resolve to A or to Am.

Open sus chord shapes

These are the sus chords most songs use. All of them grow out of an open chord you probably already know: add or lift one finger.

• Asus2: play A, then lift the finger off the B string. The open B is the 2nd.
• Asus4: play A and put a finger on the B string, fret 3. That D is the 4th.
• Dsus2: play D and lift the finger off the high e string. The open E is the 2nd.
• Dsus4: play D and add the little finger on the high e string, fret 3 (G).
• Esus4: play E and add a finger on the G string, fret 2. That A is the 4th.
• Csus2: root on the A string, fret 3, with the open D and G strings and D and G on top.
• Gsus4: G with a C on the A string, fret 3, and a C on the B string, fret 1.

Why sus chords sound unresolved

A sus chord pulls back toward the plain chord because the sus note sits right next to the 3rd it replaced. In Asus4, the D wants to fall a half step to C♯. In Asus2, the B wants to rise a whole step to C♯. When it moves, the chord “resolves” and you hear A major again.

That is the classic acoustic sound: hold a chord, flick the sus note on and off with one finger, and the chord moves without changing shape. Try D, Dsus4, D, Dsus2, D on the cards above. Only the finger on the high e string changes, and the bass note stays on the open D string the whole time.

Sus2 and sus4 can be the same notes

Asus2 is A B E. Esus4 is E A B. They are the same three notes, and the name only tells you which note is meant as the root. The same is true of Dsus2 (D E A) and Asus4 (A D E).

On guitar, the lowest note you play usually decides the name. If A is in the bass and the chord moves to A, call it Asus2. If E is in the bass and the chord moves to E, call it Esus4.

Movable sus shapes: Bsus, Csus4 and more

Any sus chord can be moved up the neck with an A-shape barre: index finger across the strings at the root fret, root on the A string. Here is Bsus4 and Bsus2 at fret 2, the shapes most chord sheets mean by “Bsus”:

Slide the same shape to fret 3 and it becomes Csus4 or Csus2; fret 5 gives Dsus4 or Dsus2, fret 7 Esus4 or Esus2. The root is always the note under your index finger on the A string.

Sus chords inside a key

A sus chord sounds most natural when all of its notes belong to the key of the song. G major has the notes G A B C D E F♯, so these all fit:

• Gsus2 (G A D) and Gsus4 (G C D) on the home chord
• Csus2 (C D G) on the IV chord
• Dsus2 (D E A) and Dsus4 (D G A) on the V chord

Csus4 (C F G) is the one that does not fit, because G major has F♯, not F. That is a quick check you can use in any key: spell the sus chord and see if every note is in the key’s scale.

Dsus4 to D on the V chord is the most common use. It delays the 3rd just before the progression returns home. See the key of G major for G, Cadd9, Dsus4 and Em7 played as one ringing family of shapes.

7sus4, add9 and other names you may see

• 7sus4: a sus4 chord with a ♭7 added, 1 4 5 ♭7. A7sus4 is A D E G. It sets up a dominant 7th chord the same way sus4 sets up a major chord.
• sus with no number: sus4.
• add9 or add2: the 3rd stays and a 2nd or 9th is added on top. Cadd9 is C E G D, a major chord with an extra colour, not a sus chord.
• sus2 vs. 2: some chord sheets write C2 for Csus2. Check the shape: if there is no E, it is the sus2.

A7sus4 to A7 is the same move as Asus4 to A: one note falls a half step, D to C♯, while the 7th (the open G string) keeps ringing.