Track structure
Build-up
A build-up is the climb out of a breakdown — a riser, a snare roll, filters opening — that tells a floor the drop is coming. It is arranged to land exactly on a phrase boundary rather than wherever it happens to finish.
In practice
A build-up points at one exact moment, so finish the transition before it starts or wait until after the drop.
There is nowhere to hide inside one. What makes that manageable is the grid a build-up lands on. A build-up is written to finish on a phrase boundary, so its length is a power of two in bars and its duration follows directly from the tempo — which means you can count into a record you have never heard and still be right about where it lands.
15.0 s
8 bars at 128 BPM
30.0 s
16 bars at 128
27.4 s
16 bars at 140
Where these come from: Arithmetic from the 4/4 phrase grid, not counts from our catalog. Our analysis reads whole tracks rather than sections — one value per dimension for the entire file — so we cannot tell you where this section begins in a given track or how long it runs. For what we can measure, see the phrase grid this rests on.
Why it matters
A build-up is a commitment. Once it starts, the room knows what happens next, and a transition that is still unresolved when it ends has nowhere left to hide — which is why DJs either complete a mix before the build or wait until after the drop.
It is also the least forgiving place to be off by a bar. Everything in a build is pointed at one moment, so an incoming record phrased even slightly wrong arrives sounding like a mistake rather than a choice.
Frequently asked
How long is a build-up?+
Usually eight or sixteen bars — about 15.0 or 30.0 seconds at 128 BPM. That is the convention of the arrangement, not something our whole-track analysis measures.
Should you mix over a build-up?+
Generally not. A build points at a specific moment, so a transition that is still in progress when it resolves fights the record rather than riding it. Finish before it starts, or come in after the drop.
What makes a build-up work?+
Tension that resolves exactly on the phrase boundary. Risers, filter sweeps and drum rolls all do the same job — they remove the sense of a stable groove so the drop feels like the answer.
Related terms
Breakdown
A breakdown is the section where the drums fall away and the track opens out — pads, vocal, atmosphere — before the beat returns. It is the natural place to mix into, because there is very little left to clash with.
Drop
The drop is the moment the full arrangement lands after a breakdown — beat, bass and hook arriving together. In most club records it is the point the whole track is arranged around, and the thing a floor is waiting for.
Phrase
A phrase is a block of bars a track is built from, usually 8, 16 or 32. Electronic music changes at phrase boundaries, so a mix that starts on one keeps both tracks structurally in step.
Energy curve
An energy curve is the shape a set makes over time — where it starts, how steeply it climbs, where it peaks. It is the plan behind a running order, and the thing a crowd feels without being able to name.
Explore: Beats-to-time calculator · Energy arc tool · Phrase · All DJ terms