Another related way that songwriters control the perceptions of their listeners is through the variety and number of chords in their music. In this book, we’ve learned how many chords function, and one of the things that has become clear is that some chords sound more exotic than others in certain contexts. Songwriters take advantage of these differences by carefully planning how these different chords are introduced in their songs. Songs using more limited chords that sound harmonically close to the home base are said to have a small harmonic scope, while longer, more complex progressions with more chords far away from home base are said to have a large harmonic scope.
Listen to this section from “Out from Under” by Britney Spears. The progression manages to use only the chords I, V, vi, and IV, but it is able to obtain a very different feel compared to four-chord songs that just repeat these chords over and over again in that order:
Focus in particular on the sound of the IV. IV is such a common chord that you would think there would be no way to make it feel new and mysterious. Harmonically the song goes back and forth between vi and I via a V⁶ chord (V in first inversion). The repetition of this pattern does little to establish a strong sense of home base because of the weaker inverted V chord; the song feels as though something is unresolved. The repetition of this pattern purposely keeps the harmonic scope limited because it uses only these three simple chords. Finally, after several repetitions of this phrase, we are hit with a IV chord for a full two measures to cadence to the next section of the song. Part of the story here is no doubt energy control as well. The harmonic rhythm slows to allow more time for the buildup. A synth string enters over the sparse guitar strum, and the volume rises slowly throughout the duration of the IV, building to a huge crescendo.
Songwriters often choose to expand the harmonic scope of their song in the bridge. The bridge is a natural choice for this because it usually occurs only once in a piece of music and serves to break up the monotony of the verse/chorus repetitions. There are many ways to introduce these new chords to your song. If your song uses I, V, vi, and IV in the chorus, you could try starting your bridge on a ii , for example. Here is a song that has a simple chorus and verse but expands its harmonic scope in the bridge.
Both the chorus and the verse of “Take A Bow” by Rihanna use the almost cliché I → V → vi → IV progression (by far the most common progression in the Theorytab library on our website):
As effective as this progression is (because otherwise there wouldn’t be so many hit songs that use it), after hearing so much I → V → vi → IV the ear is ready for a little diversity:
The bridge provides a nice contrast to the rest of the song. The ascending IV → V → vi⁷ breaks the I → V → vi → IV pattern while still not introducing any new harmony. Then the ii⁷ gives us the completely new sound that our ears want to hear. ii is a nice chord on its own, but the harmonic deprivation preceding it makes it an even better choice here.
An even more striking example of harmonic scope expansion can be heard in “E.T.” by Katy Perry. Here the verse is almost entirely static, holding steady on vi and giving the song a minor feel (something we’ll be talking much more about in the next chapter on the minor keys):
In the chorus, the one-chord progression from the verse gives way to a greater variety of chords. The progression here is still very simple, but it feels a lot more dynamic than it is because of the contrast with the verse. Perry also does an interesting thing in the melody between the two sections. It’s exactly the same. The additional contrast provided by the expansion of harmonic scope is enough to make the chorus distinct enough from the verse that we don’t get bored. The repeating melody, in turn, has a droning quality that keeps the listener in a steady groove.
In the examples above, songs are able to achieve contrast and make a portion of the music stand out more by expanding the harmonic scope in that section. It’s also possible to do the reverse. In “When I Was Your Man” by Bruno Mars, the verse uses lots of chords in their inversions and as sevenths, but the “hook” of the song is the simple chorus that follows. Here is the verse so you can orient your ears to its moderate harmonic scope:
Unlike the verse, the chorus contracts harmonically to perhaps the most basic progression in all of music, IV → V → I (pre-cadence, cadence, to home base). Even though this progression is simple, its contrast with the moderate harmonic scope of the verse makes it really stand out.