Trap

What it is

Atlanta from about 2003, formalised by Shawty Redd, Zaytoven and Lex Luger, and by 2013 the default production style for rap worldwide. Trap took Memphis rap's moving 808 and its snare on beat 3, added the hi-hat roll as a structural device, and put a keyboard player's harmony on top. The 808 stopped being a drum and became the bassline: producers began sliding it between pitches with portamento, so a single sample carries the kick and the bass and the root movement at once. Almost everything in mainstream rap since has been a variation on that arrangement, which is why the label now covers about fifteen years of very different records.

What it sounds like

Enormous low end and a busy, brittle top with a hole in the middle. The 808 slides between notes and rings for most of a bar. The snare is a short, bright machine hit landing once per bar on 3, usually with a clap under it. Hi-hats run sixteenths and then break into rolls that are faster than sixteenths, sometimes much faster, and those rolls carry the rhythmic interest that swing carries elsewhere. Above it: dark minor keys, orchestral hits, bells, and a lot of empty space between 200Hz and 1kHz where the vocal goes.

Key elements

• The sliding 808A pitched kick with portamento between notes, so the low end plays a melody. Tuning it correctly matters more than any other decision in the track.
• The snare on 3One backbeat per bar, inherited straight from Memphis. Written at 140 bpm it is the third beat, and it is what makes trap feel slow at a fast tempo.
• Hi-hat rollsBursts of triplets, 32nds or 64ths breaking out of a sixteenth-note pulse. They are the genre's main source of forward motion and they replace swing entirely.
• Dark keysHarmonic minor and Phrygian figures on bells, plucks or strings, often only two chords, with heavy reverb and a slow arpeggio underneath.
• Space in the midsThe arrangement deliberately leaves 200Hz to 1kHz mostly empty. Trap mixes are built around a vocal that has not been recorded yet.

How to get them

• 808One sine with a pitch envelope for the click, glide around 120 milliseconds, decay long enough to reach the next hit. Tune it to the root, then use a clipper rather than a limiter so the peaks flatten instead of pumping.
• Snare and clapA bright electric snare with a clap 8dB beneath it, both high-passed at 250Hz. Send them to a plate around 1.2 seconds and gate the return so the tail stops before the next 808 hit.
• HatsProgram the sixteenth pulse first, then choose two or three places per eight bars for a roll and nowhere else. Pitch each roll up two or three semitones over its length; the pitch rise is as much of the effect as the speed.
• KeysTwo chords in harmonic minor, played as a slow arpeggio on a bell or a pluck, with a large hall behind it. Keep the whole part above 400Hz so it never meets the 808.
• MixSidechain everything harmonic to the 808 by 2 or 3dB with a fast release. It is not for the pumping, it is so the sub can be as loud as it needs to be without eating the track.
• SwingLeave it at 50 percent. Trap is a straight music and applying MPC swing to it produces something that sounds like a mistake rather than like a groove.

Reference points

Shawty Redd, Zaytoven, Lex Luger, Metro Boomin, Southside and 808 Mafia, Mike Will Made-It and Sonny Digital. Named as reference points for the sound, not as endorsements or as anyone to imitate.