BB

2026-07-15T16:00:00+01:00

// Rhythm Generator

A generative step sequencer for percussion patterns. Latin, Arabic, African and Indian traditions. Pick a rhythm, generate variations, tweak them by hand, play them back, export straight to MIDI.

Built because I didn't want to hand-place every ghost note in Bitwig. Pick a tempo and density, generate a pattern, then drag the exported MIDI straight onto a Drum Machine track.

Also: a polymetric mode. Tap a step to skip it, and that instrument's loop gets shorter than everyone else's, so it drifts in and out of phase against the rest of the pattern instead of locking to the same bar.

Hope you find it useful too.

Controls

Sequencer

Variation gallery

Generate a batch of patterns at once. Click a card to load it into the sequencer above.

About these patterns

Conga (tumbao): open tones anchor the "&" of 2 and beat 4, a slap accents beat "&4", and soft bass/heel-tip ghost notes fill the gaps. Density controls how many appear.

Bongo (martillo): a steady 8th-note pulse on the high drum (mano), occasional low-drum (hembra) accents on beats 1 and 3, and "repique" 16th-note fills near the end of the bar at higher density.

Clave: the one pattern here that isn't randomised. A real son clave. 3-2 when the slider leans 3-side, 2-3 when it leans 2-side.

Shaker: a steady 8th-note pulse that fills in extra 16th-note subdivisions as density increases, running independently of the Pattern style selector.

The clave slider also biases extra ghost notes toward the first half (3-side) or second half (2-side) of the bar. None of this is strict transcription. A sandbox for exploring idiomatic-feeling variations you can program into a drum machine, DAW, or your own code (use Export JSON).

Darbuka: Dum (deep centre tone) and Tek (sharp rim tone) lay down the fixed skeleton of whichever rhythm (iqa'a) you've picked: Maqsum, Saidi, Malfuf or Ayyub. Ka is the soft ghost stroke that fills around them, density controls how many appear.

Riq: Tek answers the darbuka in the gaps of its skeleton, call-and-response style. Jingle is a scattered shimmer across the bar, density-driven.

Sagat: a steady 8th-note pulse of finger cymbals that fills in extra 16th-note subdivisions as density increases, same role as the shaker in the Latin set.

Like the clave, the Dum/Tek skeleton itself is never randomised. That's what makes a rhythm recognisably Maqsum rather than Saidi. Everything else is a sandbox for exploring idiomatic-feeling variations. Not strict transcription.

Djembe: the lead voice of a West African (Mandé) ensemble. Bass, Tone and Slap, generated and filled with ghost notes the same way Conga is. Density controls how busy it gets.

Dunun (Dundunba, Sangban, Kenkeni): the three bass drums that carry the fixed bell timeline. Dundunba lowest and sparsest, Kenkeni highest and busiest. Pick a rhythm (Kuku, Djole, Sofa or Mendiani) and the pattern is fixed, the same way Clave and Dum/Tek define identity in the other traditions. Each hit layers a soft high bell tick over the drum tone, since a bell is traditionally lashed to every dunun.

Shekere: a steady 8th-note pulse of gourd-and-beads that fills in extra 16th-note subdivisions as density increases, same role as Shaker and Sagat.

Not strict transcription. A sandbox for exploring idiomatic-feeling variations.

Tabla (Dayan, Bayan, Ka): Dayan is the right-hand treble drum, Bayan the left-hand bass. Ka is a dry, closed stroke on top. Together they lay down the theka, the fixed pattern that defines whichever tala you've picked: Teentaal, Keherwa, Ektaal or Rupak. Not randomised, the same role Clave and Dum/Tek play elsewhere. Rupak is worth a listen: it opens on khali, a silent downbeat where the bayan drops out on beat one, unusual since the first beat is normally the strongest.

Dholak: Treble and Bass, the free second drum. Generated and filled with ghost strokes the same way Bongo, Riq and Djembe are, density controls how busy it gets.

Manjira: a steady 8th-note pulse of small brass hand cymbals that fills in extra 16th-note subdivisions as density increases, same role as Shaker, Sagat and Shekere.

Not strict transcription. A sandbox for exploring idiomatic-feeling variations.

To do

• True polyrhythmic sequencing. Polymetric mode (below) isn't polyrhythm, even though the two get used interchangeably. Polymetric is what's implemented now. Rows loop at different lengths and drift in and out of phase, only realigning after the LCM of their lengths. Can take many bars. The Steve Reich phasing effect. Polyrhythm is different: two rhythms with different note groupings over the same time span. 3-against-2 within one bar, realigning every single cycle. That's what real West African cross-rhythm does (Kuku, Djole). A triplet/12-8 bell pulse against duple djembe phrasing, both landing exactly within the same one-bar cycle. Building genuine polyrhythm means moving to a finer shared grid, 24 steps/bar (the LCM of 4 and 6) instead of 16, so duple and triple subdivisions can both land exactly. Bigger change than it sounds: BAR_STEPS=16 is baked into the two-row wrap-at-32, the beat markers, and the MIDI tick math.
• MIDI and JSON export don't capture polymetric drift. Both are a static snapshot at the current loop length. The drift is a live-playback-only effect right now.
• Variation gallery cards don't generate or preview skip states. Polymetric mode only applies to the main sequencer, not the 8-variation batch.

Changelog

2026-07-16

• Added Arabic tradition: Darbuka (Dum/Tek/Ka), Riq (Tek/Jingle), Sagat, four iqa'at (Maqsum, Saidi, Malfuf, Ayyub).
• Added African tradition: Djembe (Bass/Tone/Slap), Dundunba/Sangban/Kenkeni with bell, Shekere, four rhythms (Kuku, Djole, Sofa, Mendiani).
• Added Indian tradition: Tabla (Dayan/Bayan/Ka), Dholak (Treble/Bass), Manjira, four talas (Teentaal, Keherwa, Ektaal, Rupak).
• Added a dimmed trailing stroke behind the playhead to smooth out how it reads as it moves across the grid.
• Fixed the "Using this" hint paragraphs and instrument row tags, still using the low-contrast muted colour on text. Now light, like everything else.
• Added polymetric mode. Tap a step to cycle rest/play/skip; skipped steps shorten that row's own loop, so instruments drift in and out of phase against each other.
• Added Clave and Shaker to the Latin set.
• Added 2-bar (32-step) length option, wrapping to two stacked rows per instrument.
• Added Volume control and stereo panning across instruments.
• Removed the Bitwig preset-format caveat. MIDI note mapping now generates itself from whichever tradition is active.

2026-07-15

• Initial release: conga (tumbao) and bongo (martillo), generative sequencer grid, variation gallery, MIDI export for Bitwig.

I'd love to tell you more.