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What is a Sus Chord? [A Guide To Suspended Chords]

Once you become familiar with major chords, and how they are built you have a point of reference that can then be used to build all kinds of chords. With this in mind, in today’s article, we’re going to discuss sus (aka suspended) chords.

If you’re looking for a quick rundown – Suspended chords (sus4 and sus2 chords) do not include a major or minor third, which normally defines if the chord is major or minor. This creates tension and a sense of urgency as the chord feels unresolved or suspended between major and minor. For sus4 chords, the major third is replaced with a perfect fourth, while the major third is replaced by a major second interval if a sus2 chord. Using scale degree formulas a sus4 chord uses 1, 4, and 5 of the major scale. If building a sus2 chord the scale degree formula would be 1, 2, and 5.

That’s sus chords in a nutshell, but if you want to learn more about how they are built, what they sound like, how to play them on guitar, and how to use them stay tuned!


The Sound of Suspended Chords

As discussed above, major chords are used as a point of reference for building other chord qualities. A chord’s quality e.g. major, minor, augmented, etc., describes the mood (e.g. minor chords sound sad while major chords sound happy) of the chord and is characterized by the intervals between the notes the chord consists of.

What are intervals?
Much like the term is used in mathematics to describe how many numbers lie between two given numbers, intervals in music theory describe the number of semitones between two notes. This corresponds to the frets on your guitar e.g. 1 semitone = 1 fret, 2 semitones (aka a tone) = 2 frets, and so on.

You can click here to learn more about intervals, including the name of each of the 12 intervals used in music.

Major chords consist of a root (the matching letter name of the chord and starting note of the major scale in the same key), a major third, and a perfect fifth. While minor chords (also triads) consist of a root, minor third, and perfect fifth.

While the difference between the major and minor third is only a semitone it changes the mood of the chord.

Sus4 chords, however, don’t contain a major or minor third and instead are made up of a root, perfect fourth, and a perfect fifth. Sus2 chords on the other hand consist of a root note, major 2nd, and a perfect fifth.

This means sus chords don’t resolve to major or minor and are instead suspended between the two. This creates tension or dissonance that can be used musically to add interest to a piece of music (more on this shortly).


How to Build Sus Chords using Relative and Stacked Intervals

We can use intervals in two ways, either relative to the root e.g. counting the distance from the root note to each note included in the chord.

Relative Intervals

Or we can stack intervals to build chords, meaning the interval is relative to the previous note.

Stacked Intervals

Both major and minor chords are triads. This means the chord contains three notes and is built by stacking thirds on top of one another. You can see how the notes are ‘stacked’ in an A major chord in the sheet music example below.

Stacked thirds (Sheet Music)
Major third intervals (4 semitones or frets) are preceded by a capital ‘M’, while the minor third interval (3 semitones or frets) is preceded by a small ‘m’

Are sus chords Triads?
Sus chords, technically are not triads, while they are also built using three notes, they do not consist of stacked thirds, although they are often grouped with triads.

If we’re building an Asus4 chord using relative intervals, we would begin with our root (A), and then add the perfect fourth interval which is 5 semitones above our root (D), and a perfect fifth which is 7 notes above our root (E) or a minor second (2 semitones) above the D.

Here’s an example showing the number of semitones between each note of our sus4 chord.

Semitones123456789101112
NotesAA♯BCC♯DD♯EFF♯GG♯
Asus4

If we were building an Asus2 chord (also referred to as A2) we combine our root (A), then add a major second interval (two semitones up from our root note: B, and our perfect fifth (E), or we could refer to the 5th as a perfect fourth (5 semitones) above the B.

Semitones123456789101112
NotesAA♯BCC♯DD♯EFF♯GG♯
Asus2

That’s one way to build sus chords, by knowing the intervals they consist of. And, it can be useful to understand this to really grasp what is going on harmonically, but there’s an easier way to build chords that involves counting the scale degrees of the major scale.

If you are unfamiliar with the chromatic scale e.g. all notes used in western music and sharps (♯) and flat (♭) click here to learn more.


Scale Degree Formulas for Suspended Chords

All chords consist of notes taken from their corresponding major scale. In the table below we see the 7 notes of the A major scale and the corresponding scale degrees which are simply the order of notes in a given scale.

With this in mind, the formula used to build an Asus4 chord from the A major scale is 1, 4, 5.

Scale Degrees1234567
NoteABC♯DEF♯G♯
Asus4

The formula used to build an ASus2 chord is 1, 2, 5

Scale Degrees1234567
NoteABC♯DEF♯G♯
Asus2

Scale degrees are particularly useful, provided you understand some of the basics of scales. If you need a refresher check out my article on understanding guitar scales.


How to Play Suspended Chords on Guitar

Now that we understand how sus chords are built let’s take a closer look at how to play them. We’ll stick with the Asus4 and Asus2 examples we have used above.

In simple terms, if you take an A major chord and want to make it into a Sus4 chord we need to move the major third interval/3rd scale degree (C♯) up in pitch one semitone to D. On the fretboard, this means moving one fret higher on the B string by placing the ring finger on the 3rd fret (D).

A Major and Asus4 Chords
A major and Asus4 Chord

If you aren’t familiar with chord charts, you can read my complete article here.

If playing an Aus2 chord we move the major third down two frets to (B) as there are no sharps or flats (enharmonic notes) between B and C. On the fretboard, this means lifting the ring finger and letting the B string ring out as an open string.

A Major and Asus2 Chords
A major and Asus2 Chord

Below are chord diagrams for all sus4 and sus2 chords. Keep in mind there are different ways (voicings) to play all chords. Also, note the fret numbers where applicable are added on the left-hand side of the chord charts.

Sus4 Chord Charts

Asus4 Chord Chart
Bsus4 Chord Chart
Csus4 Chord Chart
Dsus4 Chord Chart
Esus4 Chord Chart
Fsus4 Chord Chart
Gsus4 Chord Chart

Sus2 Chord Charts

Asus2 Chord Chart
Bsus2 Chord Chart
Csus2 - Chord Chart
Dsus2 - Chord Chart
Esus2 - Chord Chart
Gsus2 - Chord Chart

What if you don’t have a chord chart available?
If you know your major chords and major scales a practical way to work out suspended chords is to simply play the 3rd note of the accompanying scale, find the same note in the chord and raise it by 1 fret to make the chord a sus4, or, lower by 2 frets to make a sus2 chord.

7th and 9th chords
We don’t need to stick just to triads either. 7th chords can also be sus chords (we simply add the 7th scale degree) along with the fourth. We can also apply this to 9sus4 chords, which are 5 note chords (the 5th is sometimes left out). While there are only 7 notes in our major scale, the 9 is the 2nd note of the next highest octave.

Barre Chords

Sus4

To transform the major barre chords shapes (A and E shapes) into moveable sus chords, the same rules apply. First, identify the major third and move up one fret (sus4) or down to frets (sus2).

When we play barre chords using the E shape (as seen on the left) the third is played by our middle finger (marked with a 2 below).

Asus4 - Barre Chord Chart

If changing this to a sus4 chord simply raise the third a semitone. This can be a tricky chord shape to play, especially if you have large fingers. An alternative is to use the following shape, which can be played using the thumb on the 6th string and muting the 5th (A) with the flesh of the thumb.

Asus4 Chord Chart - Alternate Voicing

To play a sus4 chord using the A barre chord shape we must move the 4th (ring finger) up a fret as per the chart below.

Sus2

Sus2 chords can also be played using moveable barre chord shapes. If using our A barre chord shape it’s actually pretty simple. All we need to do is lift the 4th (ring) finger off the fretboard.

Dsus2 - Barre Chord Chart

You can’t really play sus2 chords using an E barre shape as the major 2nd would sit one fret lower than the barre made by the index finger.

Good luck with this one!

Playing sus chords in Drop D Tuning

If playing in Drop D, moveable sus chords are very easy to form and are similar to power chords (aka 5 chords). The two shapes below for asus2 and asus4 are simple variations on A power chords.

To play aus4 we’re simply barring the low E, A, D, and G strings at the 7th fret. To play as asus2 we add an additional note two frets higher up the fretboard and one string higher. You can hear this chord shape used in the song, Everlong by the Foo Fighters.

Asus2 and Asus4 Chords in Drop D Tuning

How and When to Use Sus Chords

We’ve discussed how sus chords are built, and some useful shapes you can use to play them, but how do you incorporate sus chords in songwriting?

As discussed sus chords are ‘suspended’ between major and minor. The lack of a third adds dissonance, introducing a lack of agreement harmonically, or instability that is released, and pleasing to the ear when resolving to a major or minor chord.

You can really hear this if you take our Asus4 chord example from earlier and follow it up with an A major chord, you can feel yourself being pulled toward the A major chord. It’s also a useful way to add variation if you’re stuck on the same chord for any length of time.

If playing a sus2 chord the same principle applies, but it doesn’t give quite the same ‘pull’ to resolve, as the major 2nd is closer to the third than a perfect fourth. As a result, sus4 chords are used far more often (so much so that you might often see sus4 chords simply referred to as sus) to create tension.

A good example of this is replacing the V (dominant chord) in a chord progression. Dominant chords provide a sense of urgency to resolve back to the tonic chord. Replacing your V chord with a sus chord can accentuate this even further.

Tension and Release

Tension and release is a key component of songwriting. And when played in open position, it’s not difficult to move between sus4, major, minor and sus2.

For example:

From Asus4 we can move the third (3rd fret B string) down in pitch two frets to play A minor or a further two frets, leaving the B string open to pal an Asus2 chord.

You can hear examples of this in music all over.

From the introduction to ‘Free Fallin’ by Tom Petty, ‘Brass in Pocket’ by the Pretenders, and just before the guitar solo in Led Zeppelin’s ‘Stairway to Heaven’ to name just a few examples.


Summary

Understanding chord construction is key to understanding music, rather than simply learning chord shapes. Sus chords are just another example of this, and once understood, can be used to build anticipation simply by delaying the resolution to the anticipated major or minor chord or to add spice to, what might be, an otherwise bland chord progression. I hope the information above helps introduce you to sus chords and incorporate them into your playing.

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About Marty

My name's Marty, I've been into guitars for over 30 years. Theacousticguitarist.com is my blog where I write about acoustic guitars, music, and home recording.