We already learned the basics of modulation in the topic “Modulation – concept“. Now that we have formed a more solid theoretical basis, the time has come to go deeper into this subject. We can start by answering a few questions:
Where can we modulate to?
We can modulate to any key, regardless of where we are, there is no restriction on that. However, the most common is to modulate to closely related keys, because our ear will adapt better to this type of transition, since there is an affinity between these tonalities. In popular music in general, modulation to two semitones or one semitone above is also used often.
What resources can we use to modulate?
The most common is to use progressions. We can make II – V – I progressions, or any other, to better prepare our ear for the change of tonality. The cadences serve as “smoothing” agents to the transitions; they prepare the way. For the improviser, they also serve as a signal for the musician to realize where the song is going. In the article “cadences and progressions“, we show an example of using cadences to make a modulation. We will see more examples here within popular songs.
However, before that, it is worth mentioning that the cadences are not the only way to smooth a transition in tonality. We can also do the so-called “diatonic modulation“.
What is diatonic modulation?
That’s when we change the harmonic function of a chord in the song; that is, we take advantage of the fact that the same chord exists in different tonalities and make a transition between these tonalities through this chord. See this example: let’s say the tonality of a song is in C major until, at a certain moment, the G major chord appears, followed by D major and B minor.
We can clearly see that the tonality has changed to D major, but the interesting thing is that the G chord belongs to both the key of C major and the key of D major. In the key of C, G is fifth degree (dominant function), while in the key of D, G is the fourth degree (subdominant function).
Moral of the story: to make this modulation from C major to D major, we changed the function of G: it stopped being the fifth degree and started being used as the fourth degree.
This is an interesting way to modulate, as we confuse the listener by making the same chord work with another function. Often, this well-used technique makes the modulation almost imperceptible; the tonality changes and the unaware listener doesn’t even notice!
Well, the definition we’ve shown so far is not the only one possible for diatonic modulation. For example, in a song in C major, after G, the C minor chord could come, in which case we would be modulating to the parallel tone using G as dominant, that is, it hasn’t changed its function, despite having taken the song to another tonality.
Therefore, a more comprehensive definition for diatonic modulation would be to use a chord present in the original key in order to take the song to another key. Many authors also call this type of modulation “ common/pivot chord modulation“.
If we were to think about each possibility of modulation, we would be here forever talking about how it is possible to change the harmonic function of a chord (we could transform a V7 into a secondary dominant; this, in turn, could become a subV7, etc. etc.). There is no point in talking about these countless cases, as it would be tedious. It is enough that the concept has been understood, because the examples and ideas will appear when we analyze songs.
In addition to this modulation, there is still the so-called “chromatic modulation”.
What is chromatic modulation?
It’s when we make a chromatic alteration in one (or more) notes of a chord from the original key to be able to use it within another key, thus changing the tonality of the song. This sentence was long, but an example can facilitate understanding: Let’s say that, once again the tonality of a song is C major. Consider the following sequence: C – Am – A – D.
The tonality here changed to D major, and the tactic was to take the Am chord and chromatically alter its third, turning it into a major chord. This A (which was previously minor and belonged to the key of C major) became a major chord, serving as a fifth degree for D (A major belongs to the D major key), concluding the modulation.
Okay, now that we know the resources, let’s show you an example of a song that contains several modulations, so you can see how the composers work in practice.
The song below has 3 tonalities: D major, G major and F# major. Observe:
- Madalena (Ivan Lins). See on Youtube.
In the first modulation, the key is D major, until the A7(9) chord, which “should” be resolved in Dmaj7 (expected resolution), ends up serving as the dominant of the dominant (V7/V7), since the D chord appears with the seventh and resolves in Gmaj7, characterizing the first modulation.
This modulation can be classified as modulation by secondary dominant to the IV degree, which is a closely related key. From that moment on, the tonality of the song becomes G major.
The second modulation occurs when the chord that was supposed to be G major appears as G sharp minor (G#m7(11)).
Right now, it is difficult to find out where the harmony is going, but the next chords will provide the clue. Right after this G# minor, comes the G7(#11) chord, which is an altered dominant, and then the F#maj7 chord appears. Therefore, we conclude that that G sharp minor acted as a second degree of the F sharp major and G7 acted as subV7, replacing the fifth degree V7 of F#, which would be C#7. From that point on, the tonality becomes F# major. Notice that this modulation went to a semitone below the previous tonality, which was G major.
The song still returns to the initial key of D major, through another modulation. In this case, modulation occurs through a dominant of the dominant (V7/V7), since E7 acts as the dominant of A, which in turn acts as the dominant V7 of D. It is worth noting that, before this modulation, a Borrowed Chord of the parallel key appears (Amaj7, belonging to the key of F#m, which is the parallel of F# major).
There are other characteristics in this song that could be analyzed separately, such as imperfect cadences, inverted chords, among other things. But since our focus here on this topic was the subject of “modulation”, we did not want to distract from the analysis.
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