project name: cyrene
project url:
author: 21echoes
description: a drum sequencer based on Mutable Instruments Grids
discussion url:
documentation url:
tags: sequencer drum midi arc grid crow


A drummer in a box for the Norns sound computer. Based on Mutable Instruments Grids by Émilie Gillet, Step by Anton Hörnquist (jah), and Playfair by tehn

Mutable Instruments Grids comes with 65,025 preset kick, snare, and hi-hat patterns (derived from the interpolation of 25 patterns). They are organized such that similar rhythms are positioned near each other in a two-dimentional grid, and the musician is able to select a position in that grid (and change that selection over time). In Cyrene, these rhythms are then fed into a sample based, monome grid-enabled step sequencer using the Ack engine, based originally on the Step script. There is also a euclidean trigger generator available for each track, based on Playfair by tehn.

UI & Controls

Landing page:


Swing page:


So what are the swing “types” and “feels”? The two swing types are “percentage-based” and “tuplet-based”.

Percentage-based swing is a common setting on most drum machines: the beat is divided evenly by default (in Cyrene, is called “0%”), and as you dial up the percentage, the beat is divided unevenly as per your percentage selection (in Cyrene, this is scaled to max out at 7/8ths of a beat at “100%”). This algorithm either runs as “8th note swing” (making 8th notes uneven but leaving quarter notes alone), or “16th note swing” (making 16th notes uneven but leaving 8th notes alone).

Tuplet-based swing in Cyrene is different. Rather than making two-note pairs at the 8th- or 16th-note level unevenly split, it re-divides the whole beat into N equal parts (a “tuplet”), then spreads out the triggers differently across those N equal parts according to different rules (called “feels”). For example, with a 7-tuplet “drunk” feel, each beat is subdivided as 2-2-2-1. With a 9-tuplet “clave” feel, every 2 beats is divided as 2-3-2-2 3-2-2-2 (or, more idiomatically for clave, 2-3-2 2-3-2 2-2). With 6 different tuples and 4 different feels, you have 24 different ways to spice up your rhythms in ways that you just can’t get with most drum machines.

Pattern & Density page:


More Densities page:

Euclidean page:

Euclidean Rhythms

Grid (optional)

Arc (optional)

Crow (optional)