In music, modulation is one of the most common things to happen in songs that you might recognize when you hear it but not know what the word is to describe it. It’s a big word and not one we would hear in everyday life.
So, what exactly is modulation in music? To find out, we first have to understand what a key is.
What is a Key?
In music, almost every song or piece can be described as being “in a specific key”.
For example, the song “Rolling in the Deep” by Adele is “in the key of C minor”.
A key just means that a song uses notes from a specific scale – so if “Rolling in the Deep” is in C minor, it uses the notes from the C minor scale – C, D, Eb, F, G, Ab, and Bb.
If a song is in a specific key – using the notes from a specific scale – we write the key signature of that scale at the start of the music.
For example, the E Major scale has 4 sharps in it, so the key signature has four sharps written out, as seen here.
If you’re still not clear on this check out our guide to keys in music here.
Definition of Modulation
Now that we know what a key is, we can understand what modulation means.
To modulate in music is simply to change a piece from one key to another.
In most pop songs that you would hear on the radio, modulations are called key changes, but they mean the same thing.
A modulation can be accompanied by a change in the key signature, but not always.
Here is a melody that starts in the key of D Major and modulates to the key of B Minor, without changing the key signature:
A pop song famous for its modulation is the Beyonce song “Love on Top” – it has 4 key changes
With modulation, the song has to stay in the new key for a while, more than just one or two bars.
If a song modulates but only for a little bit, this is called a tonicization, and the song usually then goes back to the original key.
Types of Modulation
There are many ways that a piece of music can modulate.
The main ways that it can modulate are:
- Common chord (and common tone) modulation
- Chain modulation
- Phrase modulation
- Chromatic modulation
Let’s take a brief look at each one of these.
Common Chord Modulation
Common Chord Modulation, is where a piece modulates via a shared or common chord that the original and the new key both have in common.
This chord is known as a pivot chord.
This pivot chord acts as the point that the original key modulates to the new key.
Say you’re in C Major and want to modulate to D Major – there are two chords that both keys have in common, E minor (iii in C Maj, ii in D Maj) and G Major (V in C Maj, IV in D Maj).
Therefore you can use either of these chords to pivot from C Maj to D Maj.
Here’s a notated chord progression using this idea.
The pivot chord in this chord progression is the E minor on beat 4, because that starts the progression in DMaj.
Chopin’s “Prelude in C minor” uses common chord modulation to modulate between C minor and Ab Major.
The first beat of bar 2 is AbMaj chord, which is in both keys, and that starts the progression in Ab Maj, and then the same chord on beat 4 of bar 2 then modulates back to C minor.
Common Tone Modulation is a variant of the common chord idea, but instead of a pivot chord, there’s a pivot note.
For example, this Mozart “Fantasia No. 4 in C minor” modulates from B Major to D Major via a long-held F#, which is a tone common to both keys.
A chain modulation is one that goes through the Circle of Fifths in order to get from one key to another.
This is usually done with dominant seventh chords, because they are the chords that most strongly lean to the next one in the circle, and this is called a circle progression.
For example A ⇨ A7 ⇨ D7 ⇨ G7 ⇨ C7 ⇨ F is a circle progression, and you started in the key of A Maj and modulated to the key of F Maj.
This chord progression is found a lot in Ragtime and Jazz music, so often in fact that it is sometimes called the “ragtime progression”.
Here’s an earlier example from a Classical piano piece, Liszt’s “Liebestraum” No. 3 in Ab Maj.
It starts in Ab Maj, but then bars 2-5 follow the progression C7 ⇨ F7 ⇨ Bb7 ⇨ Eb7 before finally resolving back to Ab.
Phrase Modulation is different from the previous types of modulation because it doesn’t have a chord or note that it modulates on.
Instead it just abruptly changes from one key to another.
Usually this works best with closely-related keys, like A min and C Maj in this Mozart piece, “Piano Sonata No. 11 in A Maj”.
The A min phrase in the third movement ends on a half cadence in E Min, but then immediately modulates to C Maj without a chord or note that carries over from one to the next.
Chromatic Modulation lies somewhere in the middle of the two previous approaches.
It is more musically noticeable and abrupt than common tone or common chord modulation, but it also doesn’t just change keys immediately like phrase modulation.
This kind of modulation uses a chromatic passing tone – a note that keeps its letter name (i.e. C, D, E, etc.) but adds an accidental, like a sharp or flat.
For example, to get from C Maj to D minor (or D Major), we can take the C Maj chord – C, E, G – and add a sharp to the C, so it becomes C#.
If we then also add the note A, this becomes an A7 chord, which can then resolve to either D minor or D Major.
Here is this example written out on sheet music:
Another way chromatic modulation works is by adding a flat instead of a sharp.
If you are in the key of E min, the main chord would be E, G, B. If you then took the top note this time – the B – and added a flat that chord would be E, G, Bb, which are the top three notes of a C7 chord (C, E, G, Bb).
This C7 chord then resolves to F minor or F Major, and that way you can modulate between very unrelated keys like E min and F Maj.
Here is an example of chromatic modulation in a Bach piece, titled “Du grosser Schmerzensmann”.
It contains an added sharp (on the D) that modulates the piece from G Maj to E min.
The modulation is in bar 5, on the bottom left of the video, and it occurs at 0:33.
Pop Music Key Changes – The Step Up
Likely the way most of you are familiar with modulation is with what’s more colloquially called key changes in pop music.
The example at the beginning of this article, “Love on Top” by Beyonce, is an example.
This is when a pop song simply steps up from one key to a tonally-unrelated key one, two, or three semitones higher.
This is usually done at the end or final chorus, just to give the song a bit of extra energy.
If it’s related to any of the modulation types above, it would be closest to the phrase modulation because of how abrupt they both are.
Other examples are “Love Story” by Taylor Swift, and “Penny Lane” by The Beatles, both of which modulate up by one whole tone (or two semitones):
This song, “To Be With You” by Mr. Big is a modulation of 3 semitones, from E Maj to G Maj.
That’s Modulation in Music
Modulation is a really big concept in music, and there are a lot of ways to do it.
Especially in really long pieces like symphonies or concertos, modulation is essential to keeping music interesting and to keep a piece moving.
There is a lot of information in this article, so if you have any comments or questions, don’t hesitate to post one below!