A build-up is the section just before a drop or a chorus that raises anticipation little by little. Layering changes such as adding sounds, subdividing the rhythm, raising the pitch, and opening a filter makes the listener feel that something big is coming next.
What a build-up does
To make a climax feel big, you need contrast with what came just before. A build-up is where energy is stored, a run-up that makes the following drop hit harder.
Ways to create anticipation
Common methods include gradually shortening the gaps between snares or claps, layering risers, moving chords upward, and opening a noise filter. Changing several things a little at a time, such as rhythm, timbre, and pitch, creates a more natural lift than raising the volume alone.
Why you drop out just before
One method is to stop the kick and the bass at the end of the build-up and leave a short silence. Because the ear notices the absence of low end, the kick and bass that follow at the drop feel bigger. Try a length of anywhere from one beat to one bar.
Building one in a DAW
Set a range of about eight bars and arrange it so that the first half is restrained and the density rises toward the end. Use automation to move filter cutoff and reverb amount, and place a fill or an impact at the very end to make the boundary clear.
Knowing when not to overdo it
Putting an oversized build-up before a small section can throw off the balance of the track. Decide where you want the biggest peak to be, and keep the changes elsewhere modest.
