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Drum Generation

MIDINecromancer provides producer-grade drum generation with extensive customization options.

Generation Parameters

Style

  • boom_bap: Classic hip-hop feel (kick on 1 and 3, snare on 2 and 4)
  • trap: Modern trap patterns (more syncopated, heavier 808s)
  • drill: UK drill style (aggressive, dense patterns)
  • lofi: Lo-fi hip-hop (sparse, relaxed)
  • minimal: Minimal patterns (very sparse)

Core Parameters

  • Density (0-1): Overall hit density
  • 0.3 = sparse
  • 0.7 = medium (default)
  • 1.0 = dense
  • Swing (0-1): Swing amount
  • 0.0 = straight
  • 0.5 = triplet feel
  • 1.0 = heavy swing
  • Variation Intensity (0-1): Bar-to-bar variation
  • 0.0 = identical every bar
  • 0.3 = subtle variation (default)
  • 1.0 = high variation

Advanced Parameters

  • Fill Probability (0-1): Probability of fill in last bar
  • Adds rapid snare/kick hits in last half-bar
  • Creates dynamic endings
  • Syncopation (0-1): Syncopation amount
  • Shifts off-beat hits forward
  • Creates more groove and feel
  • Ghost Note Probability (0-1): Probability of ghost notes
  • Quiet snares between main snares
  • Adds texture and groove
  • Hat Subdivision: Hi-hat subdivision (1/8, 1/16, 1/32)
  • Controls hi-hat grid resolution
  • Pause Probability (0-1): Probability of pausing per bar
  • Creates dropouts for dynamics
  • Can target kick, snare, or all

Hi-Hat Modes

  • straight_8: Straight 8th notes
  • straight_16: Straight 16th notes (default)
  • skip_step: Syncopated, skips some steps
  • roll: Roll pattern with density control

Determinism

Drum generation is fully deterministic:

  • Same project seed + same parameters = same pattern
  • Per-clip seeding uses (project_seed, clip_id, seed_offset)
  • Variation is deterministic but creates diversity across bars
  • Fill patterns use separate seed for consistency

MIDI Mapping

Drums use General MIDI (GM) drum mapping:

  • Kick: 36 (C2)
  • Snare: 38 (D2)
  • Clap: 39 (Eb2)
  • Closed Hat: 42 (F#2)
  • Open Hat: 46 (Bb2)
  • Rim: 37 (C#2)
  • Toms: 45, 47 (A2, B2)

This ensures compatibility with Ableton Live and other DAWs.

Regeneration

You can regenerate drums with different parameters:

  1. Open TrackPopover on a drum clip
  2. Adjust parameters (density, swing, variation, etc.)
  3. Preview to hear changes
  4. Apply to commit to database

Regeneration uses deterministic seeding, so: - Same seed + same params = same result - Different seed or variation = different but coherent pattern