ableton-drum-groove

name	Ableton Drum Groove
description	This skill should be used when the user asks to "make a drum beat", "write a drum pattern", "give me a boom-bap/one-drop/house/trap/breakbeat groove", "add drums", or wants a style-specific drum MIDI pattern generated in Ableton Live. Writes a drum MIDI clip onto a Drum Rack track using the General-MIDI map.
version	0.1.0

Ableton Drum Groove

Generate a style-specific drum pattern as a MIDI clip, mapped to the General-MIDI drum layout so it plays any standard kit. Groove lives in the feel — swing, velocity dynamics, and tasteful ghost notes — not just hit placement.

When to use

Triggers: "make a beat", "[style] drum pattern/groove", "add drums". For a whole arrangement use ableton-genre-cover; to humanize an existing drum clip use ableton-humanize.

Process

1. Use ableton-live-runner for build/run/kill + scaffold.
2. Create a Drum Rack track with makeTrack(..., ["Drum Rack"], [...], notes, len). The rack loads empty → tell the user to drag a kit (a style-appropriate one). The MIDI is kit-agnostic.
3. Write the pattern for the chosen style (table below), looping per bar.
4. Add feel:
   • Swing — push off-beat (and/or 16th) hats late by ~0.05–0.08 beats.
   • Dynamics — accent backbeats, soften ghost notes; vary velocities with vary.
   • Laid-back vs on-top — drag the snare a hair late (+0.02–0.03) for lofi/hip-hop, keep tight for house/techno.
   • Fills — every 4th/8th bar add a small snare/tom fill or a dropped beat.

GM drum map & style templates

KICK 36 · RIM 37 · SNARE 38 · CLAP 39 · CLOSED-HAT 42 · OPEN-HAT 46 · RIDE 51 · TOM 45/47/50

Style	Kick	Snare	Hats
Boom-bap (lofi)	1, &-of-2/3 (syncopated)	2 & 4 (dragged)	swung 8ths, soft
One-drop reggae	beat 3 (with snare)	beat 3	open-hat on off-beats
Ska/rocksteady	1 & 3	2 & 4	closed on beats, open on "&"
House	four-on-the-floor	2 & 4 (clap)	off-beat open-hat
Trap	syncopated, sparse	3 (or 2 & 4)	rolling 16ths/triplets, rolls
Breakbeat	1 & off-beats	2 & 4 + ghosts	busy 16ths

Code pattern (boom-bap with swing)

function writeBoomBap(notes, bars) {
  for (let bar = 0; bar < bars; bar++) {
    const b = bar * 4;
    notes.push({ pitch: 36, startTime: b + 0,   duration: 0.3, velocity: vary(110) });
    notes.push({ pitch: 36, startTime: b + 2.5, duration: 0.3, velocity: vary(88) });   // syncopated kick
    notes.push({ pitch: 38, startTime: b + 1 + 0.03, duration: 0.3, velocity: vary(96) }); // dragged snare
    notes.push({ pitch: 38, startTime: b + 3 + 0.03, duration: 0.3, velocity: vary(96) });
    for (let j = 0; j < 8; j++)
      notes.push({ pitch: 42, startTime: b + j*0.5 + (j%2 ? 0.06 : 0), duration: 0.15, velocity: vary(j%2 ? 46 : 60) });
  }
}

Limits

• Drum Rack is empty until a kit is dropped — say so every time.
• For sample-based drums (chop a break into a rack), see ableton-sample-chopper.

See ableton-humanize, ableton-sample-chopper, ableton-genre-cover.