Keep the listener engaged, build interesting contrast, and serve the arrangement of your song.

When listening to a batch of well mixed and mastered songs, one common characteristic that you may notice is that they all will generally change in energy from section to section. It’s a common trait for the feeling of a song to shift as it moves from a verse to a chorus or from a chorus to a bridge.

Part of what you’re noticing, especially in a good mix, is how both the combination of elements and the way those elements sound from section to section complement transitions in the arrangement. These shifts over the running time of a song create a forward motion that propels the track or pulls back on the reins when needed.

A song changes, grows or contracts, and morphs over time to keep the listener engaged and create a stronger connection. Music, by its very nature, is not a static art form. It is dynamic and full of life and emotion, and a great arrangement and mix should reflect that.

There are a few common tricks a mix engineer can call on in service of that goal:

• Use fewer tracks in verses than there are in choruses. Adjusting the denseness of instrumentation can help maintain interest and momentum. Try to thin out the arrangement on the verses or introduce something new in each section as the song progresses.
• Sculpt and shape when appropriate. It isn’t unusual for an artist to present the mix engineer with a full complement of dense tracks and instrumentation. A mix engineer can then make objective and creative decisions about where to cut, mute, or otherwise edit and alter parts to support the arrangement.
• Pan the verses narrowly and the choruses more widely. You might have the verse feature an acoustic guitar panned halfway to one side, while a chorus could have double-tracked guitars panned hard left and hard right to open up the stereo image.
• Create frequency range variations from section to section. Shape the frequency range on verses to carry less low- and high-end information and choruses to cover a more full range. This will create harmonic excitement in your mix from the contrast as everything seems to become more lush when the chorus or bridge hits.
• Dial in different effects settings on different parts of the arrangement. Use either mono effects or effects with a shorter decay time in verses and stereo effects with longer decay time in choruses. This will help the depth of your mix shift as the song progresses.
• Reach for distortion sparingly—or not at all—in verses and bring it in gradually for a chorus.This creates even more harmonic excitement than you can with EQ alone. Distortion doesn’t need to be extreme, since just a little bit can change the sound dramatically. You don't want to overwhelm the sound, so use distortion to just give it a little kick.
• Automate change in the ambient drum sounds. Bringing up your overhead and room mics in choruses will widen the stereo image of your drums and make the overall kit sound larger. Or, bringing those ambient mics down in choruses will leave more room for guitars and other harmonic instruments when they appear. Experiment with both approaches to see what style best meets the needs of your mix.

The goal is to change the dimensional image of the mix along with the song. This helps the arrangement breathe by adding width, depth, and harmonic excitement as the song develops, and then letting those elements contract or shift again when the song changes lyrically and dynamically.

Every song is telling a story, sometimes literally in the lyrics but also through the experience and mood of the musical arrangement. Every story has its ups, its downs, and its transitional periods. The mix engineer uses the tools at his disposal to frame and embellish the “plot” of the story so the listener can connect with it deeply.

Using automation while mixing

Another tool in the arsenal is automation, which can be used to achieve some of the same effects. It can be helpful to think about automation in two ways.

First, there is corrective “micro” automation, where you’re making slight detailed adjustments to even out a performance, reduce breathes, or fix inconsistent levels. It’s often a good idea to do this ahead of any compression, so the compressor doesn’t work as hard.

Second, there is expressive “macro” automation, where you’re making subtle adjustments to an entire section to augment the arrangement. Make these adjustments after compression and other processing, perhaps by automating a sub mix, bus or trim plug-in after any other plug-ins in the channel strip.

For example, micro corrective automation on a lead vocal can keep the vocal on top of the mix and emphasize particular words and phrases within the song to achieve the best emotional impact. A good use of macro expressive automation might be to emphasize a build on a particular instrument and make the section feel more dramatic.

Automation is also helpful for changing the level of tracks from section to section within a song, and you can use this mixing device as sparingly or as liberally as you wish. There are no rules for automation—some mixers despise it and others adore it, but these subtle adjustments can be helpful to supporting storytelling with the mix.

Create a connection through your song

For all of these tips, and others that you pick up along the way, use them to your heart’s content—as long as they make your mix better. They can all be effective in different scenarios, depending on the song you’re working on and the pieces in play, but a great trick is only great when it’s used purposefully and not just because you can.

Be sure you’re choosing to try something with your mix as a result of both creative and tactical intent—and that you’re exploring solutions that are appropriate and make sense for your song.

Above all, the goal of any great song, and the instruments, sounds, performances, and arrangements that live inside it, is to connect with the listener who has made an investment in your material.

Give them an experience worth their time.