Writing drum parts

Definition

Writing (or programming) a drum part means deciding who plays where on the grid, with what dynamics and how it changes between sections. The drums are the element that makes a genre recognizable before anything else, and their arrangement drives the energy of the song.

The roles of the pieces

Kick: the weight, the strong beats, the lock with the bass.
Snare / clap: the backbeat (beats 2 and 4 in 4/4; beat 3 in half-time). It is the tempo reference for those who listen and dance.
Hi-hat / ride: the subdivision (eighths, sixteenths, triplets) and therefore the feel.
Toms: fills and transitions, sometimes tribal patterns.
Cymbals (crash, china, splash): punctuation, section starts.
Percussion (shaker, tambourine, congas): a second layer of subdivision, color.

The sixteenth-note grid

A 4/4 bar has 16 positions, counted 1, 1-e, 1-&, 1-a, 2, 2-e, 2-&, 2-a, and so on up to 4-a. Basic pop/rock pattern:

kick: x.......x.x..... (1, 3, 3-&)
snare: ....x.......x... (2, 4)
hi-hat: x.x.x.x.x.x.x.x. (eighths)

Four-on-the-floor (house, disco): kick on every beat, clap on 2 and 4, open hat on the “&”s.

Dynamics and velocity

Accents: hi-hat with alternating velocities (e.g. 100 on the beats, 70 on the upbeats) to avoid the machine-gun effect.
Ghost notes: snare hits at velocity 20–45 between the backbeats (funk, R&B, neo-soul). They give groove without changing the main pattern.
Round robin: alternating 2–4 different samples of the same hit.
Microtiming: shifting the snare 5–20 ms late gives a “laid back” feel (neo-soul, J Dilla-style hip hop); shifting the hi-hat early gives urgency.

Arranging the drums by section

Intro: just hi-hat or a filtered kit; or full drums to start right away.
Verse: essential pattern, sometimes without crash and with closed hi-hat. Often half-time or with a reduced kick.
Pre-chorus: increases density (kick in eighths, snare becoming more frequent, toms), or removes the kick to create emptiness.
Chorus: cymbals (ride or crash every 2–4 bars), open hi-hat, more present kick, possible clap layer.
Bridge / breakdown: change of feel (half-time, toms only, percussion only).
Last chorus: the fullest version, sometimes with an extra percussion part.

Fills and transitions

A fill usually lasts 1–2 beats (end of a 4-bar phrase) or a whole bar (end of a section).
The most effective fill is often a gap: taking everything out on the last beat before the chorus.
Fills on toms in sixteenths or triplets, snare rolls for EDM build-ups (quarters → eighths → sixteenths → thirty-seconds over 8 bars).
Crash on beat 1 of the new section, often together with the kick.

Interaction with bass and voice

Kick and bass must have a decided relationship (lock or alternation): see the card on bass lines.
During the vocal avoid continuous fills and cymbals that occupy 3–8 kHz for too long; fills go in the pauses of the melody.

Patterns by genre (indicative)

Boom bap (85–95 BPM): kick on 1 and 2-a, snare on 2 and 4, hi-hat in eighths with 55–62% swing.
Trap (140, half-time): snare/clap on 3, hi-hat in sixteenths with rolls in thirty-seconds and triplets.
Funk: syncopated kick, snare on 2 and 4 with ghost notes, hi-hat in sixteenths.
Reggaeton (90–100): dembow, four-on-the-floor kick and snare on 1-a, 2-&, 3-a, 4-&.

Use in real songs

Clyde Stubblefield on James Brown — Funky Drummer (1970): ghost notes and syncopated snare, one of the most sampled breakbeats.
Questlove and the work with D'Angelo (Voodoo, 2000): laid-back microtiming.
Metro Boomin: hi-hat rolls and 808s in modern trap.

Practical exercise

Program 4 versions of a drum part for the same song (verse, pre, chorus, bridge) using only kick, snare, hi-hat and crash. Rule: each section changes at least 2 things. Then add ghost notes at velocity 30 and listen to the difference.

Arranging for the rhythm section, Groove, swing and microtiming, Syncopation and anticipation, Meter, subdivision, half-time and double-time, 808 lines.