Using Relative Key Changes to Make More Interesting Music
As a songwriter, key changes are a really effective way of making your
songs sound structurally and dynamically more interesting.
As a lead player, being able to recognise when key changes occur will
help you choose the right scales/notes for your solo.
This lesson will introduce you to the mechanics of key changes (often
called modulation) starting with the most natural sounding type of
modulation - changing between relative
keys. This is a good place to start because, as we'll
discover, both these keys share the same scale and therefore chords.
Watch the presentation below for the basic info, with more help further
down the page...
Relative Key Chart and Diagrams
First, we need to understand the relationship between relative major
and minor chords.
Relative major/minor chords are always a minor 3rd interval
(whole + half step) apart, with the minor chord below the
major. That's the equivalent of 3
frets on the fretboard. So we have: min - W H -
So to get from a minor
chord to its relative major, you move up a minor 3rd
To get from a major
chord to its relative minor,
you move down
a whole and half step from its root.
The table below shows this relative relationship in several keys.
The diagram below shows you how the relationship between relative major (M)
and minor (m)
chord root notes would appear on the fretboard. So wherever the root of your chord
shape is on the neck, you
should be able to find its relative chord in close proximity...
But why "relative"? (Warning: for the theory heads only!)
This isn't so important to know if you're not that interested in
theory. But in the context of key, relative major and minor keys are
said to share the same key
signature. The only difference between the two is they
represent a different tonal
center, i.e. they act as independent tonic chords of their
Remember that key signature
is not the same as key center.
Key signature is about specific notes used in the chords/scale of the
progression. Key center is about where the progression resolves in that
scale... which chord is considered "home".
Both C major and A minor, for example, share the same key signature (since they
share notes from the same diatonic scale, just starting on a different degree). But if you built a progression
around a Cmaj tonic, for example, it would have a different key center to a
progression built around an Am tonic. They both act as independent
points of resolution even though they share notes from the same "parent" scale (C major).
Regardless, what matters is that you can visualise and hear the
relationship between relative major and minor tonic chords. Then, we can move
on to using/identifying them in progressions.
Changing Between Relative Major and Minor Keys
The only difference between a relative major and minor key is
we're resolving the progression to a different chord in the same scale
(1) for the major tonic and vi
(6) for the minor tonic.
Here's how the scale would look in C major...
So we could have a progression of: Cmaj / Fmaj / Dm / Gmaj (I
IV ii V)
would resolve nicely back to Cmaj. Cmaj is therefore the tonic or
"home" of this progression. There's a certain musical "gravity" that
pulls us towards it.
That, in a nutshell, is what key
center is all about. No need to overcomplicate it. It's
all about resolution.
However, we could also resolve from Gmaj to the relative minor key of Am, Am being the vi
chord of the harmonized C major scale.
Technically, when we establish a new tonic like this, we should call
that new tonic chord 1
(lower case numeral for minor chords). But that would mean renumbering
the scale in relation to that new 1 chord. I (and many musicians in fact) prefer to just see the
relaitve minor tonic as the 6 chord of the major scale.
One scale, two relative tonics, in other words.
Use pre-tonic chords for smoother transition
Pre-tonic (Pt) chords are chords that come just before the tonic, with
their main function being to aid resolution (think of them like
signposts that tell you you're almost home!). Some
chords create a stronger pull to a tonic than others, and can help us
transition smoothly between keys.
In the table below, we have three potential pre-tonic chords - the
V, IV and ii - for moving from the minor key to its relative major...
Examples of relative key modulation
Below are some examples (with audio clips) of major I
- minor vi
key changes using typical progressions you'll hear in countless songs
old and new. I've also highlighted the "pre-tonic" (Pt) chord...
In the audio clips, you'll hear the minor progression played twice
before changing to the relative major key, again played twice before
resolving back to the minor tonic. This will demonstrate how this
relative key shift works in practice.
you obviously don't have to repeat the same progression in the major
key as you did in minor. I've just used the same chords to demonstrate
how they can still sound natural when a relative key change is used.
Progressions also don't always start
on the tonic. However, when getting to know this stuff, starting on the
tonic will help train your ear to a specific key centre.
Don't be fooled by the jargon! Tonicization is just another way of
saying "a temporary change in key/tonic".
So we might change from a
major key verse to a relative minor bridge (e.g. for just four
measures) and then return to the relative major key for the chorus.
This is a technique commonly employed in popular music and
helps to structurally and dynamically break up the song.
that second example demonstrates how we don't have to start on the
tonic chord to affirm the new key centre.
Other ideas to try
Use relative modulation to...
Play an intro in a different relative key to the verse.
Break up a more kinetic verse. For example Cmaj / Gmaj /
Cmaj / Fmaj / Am
/ E7 / Am / E7
Play a middle eight (a kind of interlude after a couple of
Play a minor key rendition of the chorus (usually after
several regular choruses). This is often called reharmonization.
Play an outro in a different key to the preceding section.
The main thing is that you have fun experimenting with different ways
in which you can use this technique. As a songwriter, it'll encourage
you to think more creatively and avoid repetition (if that's what you're aiming for). As a soloist, it'll prepare you for
playing through key changes and not get thrown off by them.