Suspended Chords
A suspended chord uses a major 2nd or perfect 4th in place of the major/minor 3rd normally found in triads. Suspended chords have an abbreviated name of sus2 or sus4. For example, Csus2 is (C D G) while Csus4 is (C F G). They are called suspended because the M2 or P4 is usually carried over from the preceding chord then resolved to the 3rd, suspending the full resolution.
Contents
PreReqs
Tonality
Suspended chords sound quite harmonic but do not indicate a clear tonality, which may make them feel tense or unresolved in certain contexts.
The M2 interval that occurs between the root and 2nd in sus2 and 4th and 5th in sus4 is slightly dissonant, but another way to look at it is to think of the 2 as a 9, so you have root, 5th, 9th. The 9th is a perfect 5th above the 5th, so you have basically stacked fifths.
For the sus4, the 5th can be thought of as a 4th below the root. Thus with the 4th below and the 4th above, you have stacked 4ths. Since 5ths and 4ths are the most harmonic intervals, it stands to reason that these chords will sound quite harmonic.
Also, by having neither a major nor minor third, they give little indication about whether the current tonality takes a major or minor form. Suspended chords can occur in both major and minor keys.
Inversions/Equivalence
The sus2 chord has the intervals:
R 2 5 R -M2- -P4- -P4-
While the sus4 has:
R 4 5 R -P4- -M2- -P4-
If we extend the sus2 for 2 octaves and align the interval pattern with sus4, they match:
Sus2: R 2 5 R 2 5 R
-M2- -P4- -P4- -M2- -P4- -P4-
Sus4: -P4- -M2- -P4-
R 4 5 R
This means the chords are basically equivalent, simply using a different root note. 2nd inversion sus2 is a sus4, while 1st inversion sus4 is a sus2. Below we see that Gsus2 and Dsus4 consist of the same notes.
Gsus2 Dsus4/A E-------------------- B-------------------- G-------------------- D--7-(A)------5-(G)-- A--5-(D)------5-(D)-- E--3-(G)------5-(A)--
Common Shapes
6 String
| Sus4 |
|---|
R |i|-|-| 5 |i|-|-| 4 |)|-|p| R |)|-|r| 5 |)|-|m| R |i|-|-| |
This sus4 is basically the same shape as our E-shape barre chords, but raising the 3rd to the 4th. This shape demonstrates the stacked 4ths on its A, D, and G strings.
5 String
| Sus2 | Sus2 | Sus2 | Sus4 |
|---|---|---|---|
R |i|-|-|-|-| 5 |i|-|-|-|-| |)|-|-|-|-| 2 |)|-|-|-|p| 5 |)|-|r|-|-| R |i|-|-|-|-| |
2 |-|-|p| 5 |i|-|-| |)|-|-| R |)|-|r| 5 |)|-|m| R |i|-|-| |
5 |i|-|-| 2 |i|-|-| R |)|-|r| 5 |)|-|r| R |i|-|-| |-|-|-| |
5 |i|-|-|-| 4 |)|-|-|p| R |)|-|r|-| 5 |)|-|r|-| R |i|-|-|-| |-|-|-|-| |
The first example of the sus2 demonstrates the stacked fifths on its bass strings. In rock playing, often only those 3 notes are played in that shape, requiring no index finger barre.
Notice that the first 2 sus2 shapes have a muted G string. Use your pinky to mute it in the first shape, and your ringer finger for the 2nd.
4 String
| Sus2 | Sus4 | |
|---|---|---|
2 |i|-|-|-| R |)|-|-|p| 5 |)|-|r|-| R |i|-|-|-| |-|-|-|-| |-|-|-|-| |
4 |)|-|-|p| R |)|-|-|p| 5 |)|-|r|-| R |i|-|-|-| |-|-|-|-| |-|-|-|-| |
|-|-|-|-| |-|-|-|-| 4 |-|-|r|-| R |-|-|r|-| 5 |-|-|r|-| R |i|-|-|-| |
Here we finally take advantage of that barre for the 4-string sus2 chord.
3 String
| Sus2 | Sus4 | 1st Inv Sus4 |
|---|---|---|
|-|-|-|-|-| 2 |-|-|-|-|p| 5 |-|-|m|-|-| R |i|-|-|-|-| |
4 |-|-|p|-| |-|-|-|-| 5 |-|-|r|-| R |i|-|-|-| |
|-|-|-|-| 4 |-|m|-|-| R |-|m|-|-| 5 |-|m|-|-| |
Harmonic Function
Suspended chords are often used to prolong the full resolution in a progression. For example, the 2nd note of the key is found in the iii, V, or vii° (or III, v, or VII in minor) chords. Rather than resolve these chords to the tonic chord, we can resolve to the sus2 chord with the tonic note as the root. This carries over that 2nd note, preventing a complete resolution. After sustaining the sus2 long enough, the 2nd resolves up to the 3rd, making the I (or i) and completing the resolution.
For the sus4, the same thing happens with the 4th note of the key, when resolving from a ii or IV chord to I (ii° or iv to i in minor). The 4th resolves down to the 3rd.
Examples
G Csus2 C V Isus2 I E--3--------3----3--- B--3--------3----5--- G--4--------5----5--- D--5--------5----5--- A--5--------3----3--- E--3-----------------
F/C Csus4 C IV Isus4 I E--1--------1----0--- B--1--------1----1--- G--2--------0----0--- D--3--------3----2--- A--3--------3----3--- E--------------------
Another common usage is to alternate between sus2, sus4 and the major or minor chord with the same root. This adds a little melody into the harmony. This can be heard most predominantly in Kansas's Dust in the Wind and Led Zepplin's Tangerine. However, it's important to distinguish that similar cases aren't often true suspensions, with the major/minor 3rd actually being played by another instrument or in a different octave. Then the effect is similar to a 9th or 13th chord, which we will cover later.
Am Asus4 Am Asus2 E E--0----0----0----0----0----- B--1----3----1----0----0----- G--2----2----2----2----1----- D--2----2----2----2----2----- A--0----0----0----0----2----- E----------------------0-----
Homework
- Know that a suspended chord is a triad that lacks a 3rd, instead using a major 2nd or perfect 4th.
- Know that sus2 is (R M2 P5), and can also be seen as stacked 5ths (R P5 M9).
- Know that sus4 is (R P4 P5), and can also be seen as stacked 4ths when inverted (P5 R P4).
- Know that the sus2 and sus4 chords are actually inverses of each other.
- Practice all of the suspended chord shapes above. Some are difficult and can be skipped if you find them too challenging.
- Know that the harmonic function of suspended chords is to retain a note from the previous chord as the 2nd/4th of the suspended chord, which then resolves to the 3rd. This typically occurs on a resolution to tonic. When dominant-function chords resolve to tonic, they retain the 2nd of the key. When sub-dominant function chords resolve to tonic, they retain the 4th of the key.
- Play the sample progression that makes use of the suspended resolution above.
- Make up a sample progression that makes uses v - isus2 - i. Make a sample progression that uses iv - isus4 - i.
- Understand suspended chords in the context of melodic playing, and practice the sample progression above that makes use of this.