A sister instrument to Ephemera

A hundred clocks. One beat.

θ̇ᵢ = ωᵢ + (K/N) Σ sin(θⱼ − θᵢ)

spread → chaos · coupling → lock · phase → onset

Scatter a swarm of oscillators, each ticking at its own speed. Raise one knob — coupling — and watch chaos collapse into a groove. The lock-up is the Kuramoto transition: the same physics behind fireflies, pacemaker cells, and metronomes on a shared table.

Entrain the swarm →Read the story

Free in browser · no account to find a beat

The idea

A drum machine that tunes itself.

Order, out of noise.

spread → chaos · coupling → lock

Entrain is a drum machine with no pattern. You scatter a swarm of oscillators, each one a tiny clock ticking at its own natural speed. Left alone they fire at random — a fog of clicks with no center.

Then you raise the coupling. Each clock starts listening to the others, nudging its phase toward the crowd. Past a critical threshold the whole swarm snaps into time, and a groove crystallizes that no one wrote.

The spread of speeds, the strength of the coupling, a few pinned leaders — those are the controls. The beat is whatever they agree on.

Made by the Ephemera team.

// a sister instrument

Entrain began as a question inside Ephemera — can a rhythm tune itself? — and grew until it earned its own door.

Same hands, same craft, opposite gaze. Ephemera looks outward at time, weather, season, and moon. Entrain looks inward, at the moment a crowd of clocks stops arguing and agrees on one pulse. And the weather still leaks in: a calm sky tightens the swarm, a storm scatters it.

Free in the browser. No account to find a beat. $19.99 once for the desktop build, or bundled with Ephemera Premium.

Because a groove is an agreement.

many phases → one pulse

Every drum machine asks you to decide the pattern first, then loosen it back toward life. Entrain starts from life — a hundred independent voices — and lets a single force pull them together.

Turn the coupling down and the pocket dissolves back into individuals; turn it up and they march. Everything between is a living groove, half-locked, breathing in and out of time.

You don't program the pulse. You raise the coupling until the swarm agrees on one.

Four states

One knob. The whole transition under your thumb.

The journey of the order parameter r from 0 (pure noise) to 1 (perfect lock).

Scatter

r ≈ 0 · every clock for itself

Incoherent fog — arrhythmic texture, generative dust.

Drift

weak K · clusters forming

Sub-groups lock first — shimmering polyrhythm, half-time pockets.

Lock

K > Kᶜ · the swarm agrees

A tight, emergent groove no one authored.

Lockstep

K → ∞ · one phase

Rigid machine pulse, every voice nailed to the grid.

The Swarm

Scatter 16 to 128 oscillators, each with its own natural tempo. The wider the spread, the harder they are to tame.

The Coupling Knob

One control rules them all. Slide from chaos, through the critical threshold, into a hard lock — and hear the transition happen.

Leaders & Followers

Pin a few oscillators as pacemakers and the swarm entrains to them, so you steer the groove without writing a single step.

Coherence Meter

A live readout of the order parameter r, from 0 (pure noise) to 1 (perfect lock). Watch the room come into time.

Under the hood

What you tune, what it emits.

Swarm

16–128 voices

Each oscillator carries its own natural tempo and one drum voice.

Coupling

one global K

The master force. Below Kᶜ is chaos; above it the groove emerges.

Input

MIDI + keys

Tap a tempo seed, or pin leaders live from a controller.

Export

MIDI · WAV · stems

Bounce the emergent groove, render stems, or capture the swarm as a pattern and share by link.

Scatter the swarm→

Raise the coupling→

Pin a leader or two→

Launch or send to Dimensional

Pricing

Free forever in the browser.

One-time purchase · no subscriptions, ever · free forever in the browser

Free Web

The full swarm in your browser. Scatter, couple, pin, audition, and share by link. No install, no account.

Launch in browser

Desktop

$19.99

Native app. Offline. Save and load swarms, audio + MIDI export, VST3 hosting in your DAW, lifetime updates.

Get the desktop app

Ephemera Bundle

Included

Entrain ships free with Ephemera Premium and lives as a rhythm module inside Dimensional too.

See Ephemera

Questions

Before you scatter the swarm.

Is it really free?

Yes. The full instrument runs in your browser with no install and no account. The $19.99 desktop app and the Ephemera bundle add offline use, file save/load, export, and VST3 hosting, but you never have to pay to find a beat.

What makes a self-syncing swarm different from a drum machine?

A drum machine plays a pattern you wrote. Entrain plays a pattern that emerges: dozens of independent clocks pull each other into time, and a single knob decides how tightly. You tune the force, not the steps.

Can I control the groove, or is it random?

Both, on a dial. Pin leaders to set the pulse, narrow the frequency spread to lock harder, widen it to let the pocket breathe. Same seed plus same settings always give the same groove.

How does it connect to Timbre and Dimensional?

A Timbre cube can pulse Entrain's leaders (authored steps seeding the swarm), and Entrain's emergent onsets can be captured straight into a Timbre corner. In Dimensional the swarm scatters into 3D space and coherence rises as the bodies cluster.

Raise the coupling.

Scatter a swarm of clocks and listen to them find one beat together — free in your browser.

Entrain the swarm →