Trap

Trap clocks at 130 to 170 BPM but is felt in half-time at 65 to 85, which is why the snare or clap on the 3 feels so heavy. The signature kit is a Roland TR-808: a deep, pitched sub-bass kick that doubles as the bassline, snares or claps on the backbeat, and rapid 16th-note triplet hi-hats. Synth pads tend toward minor-key horror-movie tonality. Vocals are typically autotuned and sit between rapping and melody, with ad-libs ('skrrt,' 'yeah') filling the space between bars. Mastering is mid-scooped and bass-heavy.

T.I.'s 'Trap Muzik' (2003) put the term in the mainstream — a 'trap house' is a place where drugs are sold. Gucci Mane and Young Jeezy fleshed out the lyrical world in the mid-2000s, and producers Shawty Redd, Lex Luger, Zaytoven, and Mike WiLL Made-It standardized the sound. Migos's triplet flow on 'Versace' (2013) and 'Bad and Boujee' (2016) became the template every subsequent rapper learned. By the late 2010s, Future, 21 Savage, Travis Scott, Lil Baby, and Cardi B had made trap the de facto sound of rap radio, and 'trap EDM' (Baauer's 'Harlem Shake,' 2013) cross-pollinated with dance music.

Count the hi-hat subdivisions — they typically flip between straight 16ths and triplet 16ths within a single bar, and the producer is doing the work to make that transition feel natural. Listen for the 808 doubling as both kick and bassline; when the kick changes pitch, it's playing a melody. The space between vocal lines is filled with adlibs, panned hard left and right.

Single: Migos, 'Bad and Boujee' (2016) for the canonical triplet flow. Album: Future, 'DS2' (2015), or for a more recent reference, 21 Savage and Metro Boomin, 'Savage Mode II' (2020).

The Roland TR-808 was a commercial failure on release in 1980 — Roland discontinued it after three years because its drum sounds were considered too unrealistic. The remaining stock sold off cheap and became the foundation of two genres (Miami bass and trap) and most of pop production after 2010.