Sonic Functions: The Producer's Alternative to Harmonic Functions in Modern Music

Also, note that when the tension is released (3:00) it's not due to the chord change from ii to IV, but thanks to the return of the regular drum beat and the vocal hook, as well as the beefing up of the low end and other key portions of the frequency spectrum.

So despite this song being tonal, in the sense that it uses a major key and diatonic triads as traditional tonal pieces, It's clear that the "functionality" here is sonic, not tonal.

After digging into a mass of pop songs, it became so obvious to me that sound production had assumed the same role that was once almost the exclusive domain of tonal functions, that it was very surprising to me that no one thought to slap this label on the phenomenon.

​However, there are two key differences:

Otherwise, sonic functions behave like tonal functions, in the sense that they govern the tension/release cycles in songs and can be expressed on multiple structural levels.

There are three primary sonic functions:

The most straightforward way to think about them is on the section-to-section level. A "normal" sonic progression would look something like this:

There are also more sections, like the bridge, which normally functions as a sonic buildup, and the postchorus, which is usually a climax.

But before I get into all of these different situations and sections, I want to define the sonic functions a bit more and explain how they work.

The buildup is a bit more complicated (and interesting, in my opinion). While the setup and climax are defined by their relative sonic energy, the buildup is defined by an increase of tension that causes the listener to anticipate the arrival of a climax. This tension buildup may or may not correlate with an increase in sonic energy.

More precisely, the most common ways to achieve a buildup of tension are:

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You may have noticed that the first to items in this list seem contradictory. However, the unifying factor is that all of the above techniques generate motion away from the baseline sonic energy and toward the climax.

The first technique--adding sonic elements--amps up the energy without yet reaching a climax, mentally moving the listener in the direction of the climax and causing them to anticipate its arrival.

Listen, for example, to the prechorus (0:31) in Charlie Puth's "Boy". Following a very thin texture in the verse, Puth adds backup vocals and more body to the synth. 

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The second technique--removing key elements--has the effect of creating a sonic void. It is even more effective at amping up the tension than adding elements because it creates a sonic void, making the listener crave for the return of those key elements.

A great example of this is Emily Warren's recent collab with the Chainsmokers, "Side Effects". The most dominant sonic element in the verse (outside of the vocals) is the bass, which makes its removal in the prechorus (0:22) jarring, almost like having an imaginary rug pulled from beneath our feet. 

​Perhaps the most effective method of generating tension, though, is the third technique--gradual gestures--most of these are also known as risers. They are fundamental to EDM buildups and are some of the most important imports from EDM to pop.

These gestures include filter sweeps, reverse reverbs, gradually pitching up various elements, intensifying the drums, and any other elements that creates the sonic illusion of upwards motion.

When they form an EDM-type buildup, these gradual gestures are often drawn out and added one-by-one to intensify the buildup, like in Calvin Harris and Rihanna's "We Found Love" (1:44-2:00):

Notice, for example, how just prior to the arrival of the chorus in Bebe Rexha's "I'm a Mess" (starting ~0:42), the low end is abruptly filtered out, the low knocks are replaced with high claps at double the speed, and a background vocal suddenly takes over and is gradually pitched up, drawing our attention "upwards" to make the following "drop" more effective.

A cadence is widely understood as a musical stopping or resting point, and the climax does not fit that criteria. A climactic section by its definition is very intense and does not let up until the music moves on to the next section, which usually kicks off another setup or buildup.

In fact, real cadences are extremely rare in modern pop. There are occasional melodic cadences, but pop songs generally want the listener to physically move to the music, and resting points can sabotage this goal.

Is it possible to generate a cadence in pop? Sure, but unlike building up tension or arriving at a climax, which only requires some elements of the musical texture to participate, a real cadence requires all elements to 'agree'.

If the harmony and melody arrive at the tonic, but it's on a weak metric beat, or the sonic texture retains a high level of energy, it's not going to sound like a cadence.

If the sonic energy relaxes but the pitch material generates functional tension, it's still not going to sound like a cadence.

Everything has to work together to create a cadence, and this generally doesn't happen in today's pop, except in some rare cases like Tove Lo's "Timebomb", which I mentioned in a previous post.

It should be noted, however, that cadences are possible, and more importantly, that although setup, buildup, and peak are the main and most important sonic functions in the genre, they are not the only possible ones.

The "Timebomb" example suggests that there can be a resting function, as long as it works along with the other musical aspects.

The outro of "The Night is Still Young", which I mentioned at the beginning of this post, features a gradual filtering of the music, which could be described as a diffusion sonic function.

The possibilities are there, but they are not nearly as common in the genre as the three main functions.

Take a look, for example, at Demi Lovato's "Sorry Not Sorry".

The first prechorus adds more layers after a relatively chill verse.

By contrast, the second prechorus happens after there's already been a 'takeoff' of sonic energy. So, like in "Side Effects", removing the low end pulls the rug from under the listener's metaphorical mental feet, creating even more tension.

The bridge, as bridges normally are, is on another level in terms of building up the tension. It also 'pulls the rug', but in this case it happens immediately following a climactic chorus, which makes it a lot more intense.

And on top of that, the "Rise" subsection of the bridge uses a combination of rhythmic techniques and noise to REALLY push the tension. 

But there is more depth to song structure.

Each meta-section is a grouping of several sections, which makes the song structure look something like this (the meta-sections are represented by the orange bubbles):

So, while I discussed how sonic functions operate on a section-to-section level, there is also a progression between the meta-sections, on a 'deeper', larger scale structural level.

The first meta-section, labeled A, although it contains an internal progression of setup-buildup-climax, also operates as a large-scale setup.

The second meta-section is labeled A' because melodically it usually repeats the sections from A. However, sonically this meta-section typically pushes the energy forward and functions as a large scale buildup.

The third meta-section, labeled B, starts with the 'twist in the plot', or the bridge, and ends on the biggest climax (the chorus and/or postchorus), which functions as both the internal climax of B and the climax of the entire song.

So, generally speaking, we can map out the zoomed-out sonic progression of a typical pop song like this:

Let's go back to Bebe Rexha's "I'm a Mess" and take a closer look at the prechorus (0:24-0:44):

Halfway through the prechorus, a repeated knocking sound is introduced, which is gradually pitched up and made louder. This is now the internal buildup, which was set up by the earlier removal of the rhythmic elements.

However, this is not the buildup that actually leads to the climax. It's the sequence between 0:42-0:44 (the filtering out of the low end; the high claps; and the pitched up vocal) that finally amps up the tension to the degree that makes the arrival at the chorus so satisfying.

Within the internal structure of the prechorus, everything that came before this sequence was the setup to it.

The graph above shows these processes and how much depth there is to the sonic structure. I even left out the noise sweep at 0:33 that would divide the first half of the prechorus and add another structural layer.

The more you explore internal processes, the greater your intuitive understanding will be of the level of detail required to make great songs effective.

As sound production became more and more dominant in shaping the musical roller coaster in pop songs, the role of tonal functions was gradually weakened.

I can't identify a specific turning point, but I can point to specific songs and albums that triggered my awareness of this process, such as Britney Spears's albums, Blackout (2007) and Femme Fatale (2011), as well as the aforementioned Rihanna and Calvin Harris song, "We Found Love" (2011).

The one thing I can say for certain, though, is that EDM's takeover of pop has a LOT to do with the acceleration of this process, and that's mostly from the current decade.

Some of the 'symptoms' of the weakening of tonal functions in pop music include:

But there are several differences:

It wouldn't be a terrible idea, however, to try to analyze classical pieces, or music of any genre, for that matter, from the perspective of sonic functions.

Composers routinely included gestures that can be analyzed in those terms, such as changes in the instrumental texture and range, or gestures such as crescendo/diminuendo.

Moreover, great performers focus on sonic gestures as an important tool for musical interpretation, so analyzing different performances of the same piece through the lens of sonic functions also has potential for generating insight.

In any case, I am not trying to paint a picture of absolutes. Sonic functions have always been around to a certain degree, but were not typically a focal point for analysis because of the factors I mentioned above.

And tonal functions haven't completely disappeared from pop. Some songs still use them to varying degrees, although in most cases the functional relationships are contained in the chord loops and there is rarely large-scale tonal progression.

Sometimes, the two dimensions correlate perfectly, like they do in the example I mentioned earlier - Demi Lovato's "Sorry Not Sorry":

But more and more the two dimensions diverge, which creates super interesting tension and super satisfying release.

The most common example of this is the pop-drop, a term coined by Charlie Harding and which I wrote about in my recent post about the postchorus.

In a typical pop-drop, the chorus, which is traditionally the song's climax, is transformed into a buildup, and the climax is delayed until the postchorus.

Here's an example from a recently released song - Zedd and Elley Duhé's "Happy Now":

The texture in the chorus is first stripped down and later starts building up by: 1. Re-introducing the drums 2. Adding a noise sweep 3. Removing both the drums and the noise sweep AGAIN 4. Reverse vocal reverb into the pop-drop.

Let's look at this buildup in the chorus a bit more closely:

There are also songs that flip the relationship between the two dimensions on its head, like Machine Gun Kelly and Camila Cabello's "Bad Things", in which the chorus starts off as the sonic setup and the verses intensify. At the end of the song, however, the chorus returns to its conventional role and finally acts as a climax.

If you are a producer, or even if you are strictly a songwriter who collaborates with producers, analyzing songs with a focus on sonic functions, structural levels, and the relationship between the two dimensions can be extremely beneficial. It has the potential to give you a new perspective and enhance your ability to plan the large-scale sonic arc of the song, as well as to help you understand the importance and function of the smallest details that make up great songs.