If you’ve taken music theory, at some point, you probably learned the circle of fifths. It offers a solid foundation in understanding how music works.
But you may not have even thought about it in a while.
It’s helpful to have a chart that shows you how many sharps or flats are in every key. And, the circle of fifths can even be used to build scales, modes, chords, and progressions.
But what else can we do with the circle of fifths? How can we get creative with it? Here are some thoughts.
Have Some Fun With Slash Chords
What is a slash chord?
It’s any chord that looks like this: D/F#.
Essentially, it’s a triad with a different bass note underneath.
Normally, with a D chord, you would simply add a D bass note. But depending on the song or chord progression, you could, or might even want to, add a more interesting bass note.
Slash chords can add some interest, variety and movement to your comping or rhythm playing.
Of course, here we’ll take advantage of the circle of fifths to identify possible slash chords.
D/F# happens to be a common slash chord. So, looking at the circle of fifths diagram, we know that F# is four spaces to the left of D.
A D/F# chord works well in the key of D. It could also work in the key of G, where the seventh note is an F#, but to a lesser extent.
We’ll primarily concern ourselves with the key of D here. As a refresher, the notes in the D major scale are:
D, E, F#, G, A, B, C# and D.
We can see that D and F# are a third apart. No wonder F# works so well as a bass note.
After all, a D major chord is made up of the notes D, F# and A. F# is already a part of a D triad.
So, if we wanted to create slash chords in other keys, we could follow the exact formula I just laid out.
For instance, if we started with G, we could move four spaces to the left to find B. That’s how you would get the G/B chord.
Again, we can look at the G major scale to identify the exact relationship between the notes:
G, A, B, C, D, E, F# and G.
B, as expected, is a third above G. And, a G triad is made up of the notes G, B and D.
If you’ve never played slash chords before, this should prove a fun exercise.
Now, you might be asking yourself why you’d want to play a slash chord in the first place.
One of the most common reasons slash chords are used is to emphasize specific notes in a bass line while creating harmonic interest with the chords.
The intro/verse section of “Stairway to Heaven” by Led Zeppelin is a great example.
Depending on what sheet music you’re looking at, results may vary, but this is basically what’s happening:
Am, Amadd9/G#, Am7/G, D/F#, Fmaj7, G/B, Am
Plenty of slash chords, right?
But what’s happening between Am and Fmaj7 is what we would call a chromatic descending bass line. The bass is only moving a half step at a time.
From a theory perspective, it shouldn’t work. But it sounds so good.
So, what’s happening in the bass is this: A, G#, G, F#, F
See what I mean?
This is merely a starting point for slash chords, which can offer some fun possibilities in your own music.
As you can see from the Led Zeppelin example, you can get creative with it.
The great thing about the circle of fifths is that related key signatures live right next to each other.
So, to the left of C, we have G, and to the right, we have F.
That means the key of G and key of F are closely related to C.
This is a good jumping-off point for modulation, which is also known as a key change.
Though key changes may not exactly be in vogue in pop music these days, if you use this technique correctly, it can be a powerful tool for creating movement, evoking emotion, and shifting mood in your songs.
There are many ways to modulate, and as far as I’m concerned, there is no right or wrong. You are free to explore and experiment and see what feels right to you.
But it’s always best to establish a solid theoretical foundation before we start mixing things up.
So, let’s talk about modulation in more detail.
First, we have what’s called relative key modulation.
What is a relative key? It refers to major and minor scales that have the same key signature.
A minor is the relative minor to C major. D major is the relative major to B minor. And, so on.
Some (though not all) circle of fifths diagrams show the relative minor keys on the inside of the major keys, making them easy to identify.
Transitioning between relative keys is so easy that the change is barely even noticeable. To that extent, it could even be argued that relative key modulation doesn’t exist.
As a lead player, when I’m playing in C or Am, I don’t distinguish the two. I treat them the same, except when it comes time to resolve.
But you could, for example, hold off on playing a certain chord, like the vi chord, until the chorus.
If the verses were in a major key, shifting to a relative minor key during the next section of music would grab the listener’s attention.
Second, there’s parallel key modulation.
A parallel key describes any two keys with the same tonic. So, for example, E major and E minor.
Looking at the circle of fifths diagram, to find the parallel key, we would need to shift four spaces to the left.
If you do this with E, you’ll notice that you land on G. G’s relative minor key is E minor. See how it comes together?
Transitioning to parallel keys within the context of music is relatively simple.
For starters, the dominant chord is the same in both keys. In this instance, that would be B7. Since both E major and E minor have this chord in common, you can use it to make the transition.
The other method is to borrow chords from the key you’re looking to transition to. It could be the IV chord, for instance.
In this instance, if we were transitioning from E minor to E major, the IV chord in the new key would be A.
There are different ways of creating the transition. Experiment and have fun.
Third, we have modulating to related keys.
I started off this section talking about related keys.
Looking at the circle of fifths, we know that D and E are closely related to A, because they share several notes and chords in common.
The further you move around the wheel, the less related the keys are. So, you couldn’t get much further apart from C than F#.
But F and G would be closely related to C.
We know that from looking at the circle of fifths, but let’s further validate this by looking at the chords that belong to each key:
So, the keys of C and F have these chords in common: C, Dm, F and Am.
The keys of C and G have these chords in common: C, Em, G and Am.
So, you can take advantage of common chords to create smooth modulated transitions.
Fourth, there’s common chord modulation.
Basically, we’ve already talked about this with related keys.
Again, you would first identify what chords the two keys have in common and utilize those to create a smooth transition.
Finding related keys is easy on the circle of fifths because they are always close together.
Fifth, there’s a variation on common chord modulation, which is called altered common chord modulation.
There are plenty of keys that may not share a chord but do share the same root note of a chord.
For instance, the vi chord in the key of F is Dm. And, the I chord in the key of D is obviously D.
So, if you wanted to create a transition from F to D, you could take advantage of this fact.
Using the circle of fifths diagram, we can see that F’s relative minor key is D minor, so extrapolating from there, it’s not hard to find another key that has a D major in it. The key of G certainly does, and so does the key of A. Not surprising considering they are related keys to D major.
Sixth, we have common tone modulation.
This is like common chord modulation. The difference is that you aren’t required to use common chords at all. You only need to use a common tone between keys.
It should be obvious that the C note belongs in the key of C. But there are plenty of other keys that use the same tone. Unsurprisingly, the related keys do. So does the parallel key.
Again, we can easily find these using the circle of fifths.
Of course, there are other keys that have a C note in them, and we can rely on the circle of fifths for this information too.
Finally, we have modulation by step.
Most commonly, this refers to songs that modulate by a half step or a whole step, though wider jumps are sometimes employed.
Usually, these types of transitions happen abruptly and there is very little set up for it.
But this type of modulation is nevertheless effective because it can introduce some drama to the song. It can often reach a new emotional high after a modulation like this.
Now, because the circle of fifths is organized by fifths (surprise, surprise), we can’t merely move one space to the right or left to find a half step or whole step.
C# is obviously a half step above C. But it’s located five spaces to the left of C.
A whole step is a little easier to find – it’s just two spaces to the right of C, which is D.
You can use the same formula with all tonal centers to find your half-step and whole-step jumps.
Although it might seem tedious to use the circle of fifths in the ways suggested, the more you practice with it, the greater your understanding of it will be.
You can become a master of the circle of fifths if you keep analyzing how whatever song, melody, riff or solo you’re playing connects to it.
You’ll get a better sense of how key signatures and scales work, how they’re related to each other and where the sharps and flats go.
So, come up with some of your own ideas. Get creative and have fun with the circle of fifths.