Suspended chords are a godsend for songwriters. They are the kings and queens of tension and release, but rarely are they used to their full potential. Let's take a look at how suspended chords can be used effectively in a song-writing scenario.
Suspended chords cause "suspense" by nature, hence their name. There are only two notes that can be suspended within a chord, and they are the major 2nd, and perfect 4th above the root of that chord. For example, with C, either the D (2nd) or the F (4th) could be suspended, and in each case they replace the 3rd of the triad, regardless of whether that 3rd is major or minor.
It's often easier to see this in context:
The first bar shows a C Major chord. The note on 5th fret B string is an E - the major third of C. As you can see, in the second bar, this note has been raised a semitone, now becoming F, the perfect 4th of C. The 4th (F) has replaced the 3rd (E), so this chord is now a Csus4. In the third bar, the E has been lowered a whole tone to a D, the major second of C. Again, the 3rd has been replaced, so we now have a Csus2 chord.
So why is this important? Well, by looking at it theoretically, you can see where the dissonance is created within the chord. In a sus4 chord, the 4th and the 5th clash with each other and, as humans, we naturally want that clash to go away, or "resolve." The same happens with sus2 chords between the root and the 2nd.
The most common use of suspended chords is using a sus4 chord and resolving it to its major counterpart (Csus4 - C or Fsus4 - F etc.) This is tried and tested, and works especially well towards the end of a section by using it on the fifth chord of the key. For example, in C Major, the fifth chord is G Major, so a turnaround such as Gsus4 - G - C will sound very resolved. (Adding a minor 7th to the G chords will create even more tension, and consequently a greater sense of resolution: G7sus4 - G7 - C).
However, this also works wonders for modulating into the parallel minor, as the fifth chord of the minor scale is often turned major or dominant to create tension. So instead of resolving back to C major at the end of that progression, it would modulate to Cm (G7sus4 - G7 - Cm). Voila! You are now in C minor.
But these are not the only uses for suspended chords, despite other uses being hard to come by. By knowing the theory behind the notes within suspended chords, we know that there is no 3rd, which is the note that gives the chord its major or minor tonality.
This allows us to completely disguise the gender of the chord, and leave the listener in "suspense."
Let's take a look at a simple chord sequence C - F - C - G. What key is it in?
C Major. Hands down.
Now let's alter that sequence: C - Fsus2 - C - Gsus2. What key is this in?
Well, it could be in one of two keys! Either C Major or F Major (C Mixolydian) - I'll be referring to modes from now on. And why is that so great? Well naturally, the listener is going to hear it as C Ionian, so you, as the songwriter, could give them that impression for the first two verses and choruses. Then when the middle eight comes along, you might throw in a G minor chord. The listener now has a much stronger sense of what key it is in, and all the suspense has faded. Not only that, you've chosen the less obvious of the two keys, something that will probably interest the listener.
But that's not all. You could, if you were really trying to mess with your audience, not even give away the major or minor tonality of the root chord. Take this progression:
Csus2 - Gsus4 - Fsus2 - Fsus2
There's no 3rd, 6th or 7th of C in any of them chords, which means the sequence could be in C Major, C Dorian, C Mixolydian, or C Aeolian! And when does the listener find out? You decide. Until then they don't even know if it's major or minor.
This allows us to play freely with any melody that may occur in the song. For instance a singer may use the major 3rd (E) in their melody the first time through the progression, but then use a minor 3rd (Eb) as part of the same melody the second time round. And because there's nothing in the harmony for it to disagree with, both will work.
You may be reading this thinking, "well why not just play a C note all the way through and then the listener won't have a clue what key it's in." Of course, you could do this. But there would be no "suspense" - no clash between two notes that the listener naturally wants to hear resolved.
About the Author:
Sam Dawson is a singer/songwriter who specializes in fingerstyle and percussive guitar. For more songwriting tips, sign up to his free songwriting email course.