𒀭
𒌓
𒈗
𒆳
Source
Shape
Mod
Mix
Space FX
Out
Presets:
MIDI: None
Oct: 4 Vel: 100 ← → octave · ↑ ↓ velocity
Steps
BPM
Swing 0%
Gate %
Key
Drums Mix
◇ audio suspended

📖 Synth Guide

You don't have to wire anything. Click Osc and you have a working synth — an Output appears and the cable is drawn for you. Every module you add after that joins the signal path automatically, at the point where it belongs: sources stack in parallel at the front, then tone (Filter, EQ), then shape (Envelope), then level and position (Gain, Pan), then space (Chorus, Delay, Reverb), then the glue (Compressor, Limiter) just before the Output. Add a Filter after a Reverb and it lands before it, where a filter goes — the order you click things in doesn't decide the order you hear them in. Delete something and the chain closes over the gap. Hit a preset up top for a finished patch in one click.

Changing the order

Order is the whole of sound design, so it's a choice, not a consequence of what you plugged in first. Use the arrows in a module's header to walk it up and down the chain — filter before delay is a different instrument than delay before filter. ⌗ Tidy re-lays the rack out left-to-right in signal order, so what you see matches what you hear.

Cables are still real, and still yours if you want them: tap an out port and then a glowing in port, or drag from one to the other, for parallel paths and feedback loops the automatic routing won't build on its own. Compatible ports light up and the rest dim. Tap a cable to remove it. Hand-drawn cables are never overwritten by the auto-routing.

Modules

Oscillator
sine = pure/smooth · saw = bright/buzzy · square = hollow/retro · triangle = soft/mellow
Filter
LP cuts highs (warmth) · HP cuts lows (thin/bright) · BP isolates a band · notch scoops one out. Cutoff = where it cuts, Res(onance) = emphasis at the cutoff. Slope = how steeply (−12 gentle → −48 brutal). Drive saturates the signal before the filter, so high Res screams instead of thinning out — the classic acid sound. Push Res near max on LP and it self-oscillates into a playable sine.
LFO
Slow modulation for movement. Pick what it drives from its Drives menu — every parameter in the rack is listed, and choosing one sets a depth range that suits it (Min/Max are the two ends of the sweep, Rate is how fast). Pitch = vibrato · Filter cutoff = wah · Vol = tremolo · Pan = auto-pan. A dashed violet line shows what it's driving. Modulation isn't audio, so no cable can carry it — that's why it's a menu.
FM (Frequency Modulation)
Patch one oscillator's out into another's FM input to modulate its pitch at audio rate. FM Amt = depth in Hz of frequency deviation. Set the modulator at a simple ratio of the carrier: 1:1/2:1 = harmonic (clean, organ-like), 3.5:1+ = inharmonic/metallic (bells, e-piano, gongs).
Coarse and Detune (on the Oscillator)
Coarse shifts the oscillator in semitones — the octave switch on a hardware panel. −12 makes a sub-oscillator under your other oscillators; +19 puts an FM modulator at a 3:1 ratio; +7 is a fifth. Detune is the fine tune in cents: two saws a few cents apart beat against each other, and that beating is most of what people mean by "warm".
Release and Pan (on the Oscillator)
Release is how long a note takes to fade once you let the key go, so notes breathe out instead of being cut off — that abruptness is a large part of why software synths sound stiff. Short (0.05) is a pluck; a second or more is a pad you can play chords on, since each note hangs while you find the next. Patch an Envelope and its Release takes over the fade — this still decides how long the voice is held open for it, so set it at least as long. Pan puts each oscillator somewhere in the stereo field on its own: pan two detuned saws to −0.6 and +0.6 and the patch opens up wide, which is a different thing than panning the finished sound with the Pan module.
Mod Env — the second envelope
Every subtractive synth since the Minimoog has had two envelopes: one for loudness, one for the filter. The ADSR module is the first; this is the second. It sits outside the audio path like the LFO, and its Drives menu points it at any parameter. Point it at Filter · Cutoff with a fast Decay and no Sustain and every note opens bright and snaps dark — that is what a pluck is. Slow Attack on a pad makes the note bloom. Point it at Pitch with a short Decay and you have an 808 kick. Amt is how far it pushes, as a fraction of the target's useful range; negative pulls the other way.
Envelope (ADSR)
Attack = fade-in time · Decay = drop after peak · Sustain = held level · Release = fade after note off. Patch it between an oscillator and Output and it re-fires on every note — piano keys, MIDI, and the sequencer all retrigger it, so a short Decay gives plucked/percussive steps instead of a flat on/off. Drag the handles on its curve (or the sliders) to shape it — the graph and sliders stay in sync.
Delay
Echo effect. Time = gap between repeats · Feedback = how many repeats · Mix = dry/wet balance.
Reverb
Room simulation. Size = room size · Damping = high-freq absorption · Mix = how much reverb.
Gain
Volume control — use to balance levels between modules.
Noise
white = all freqs equal (hiss) · pink = bass-heavy (wind) · brown = deep rumble.
Audio File
Drop an audio file onto the module (or click Load) to play and loop it — drop in several to build a multi-track mix. Vol sets its level.
Audio In
Live audio from an interface, mic or hardware instrument, processed by everything downstream. Click Enable, allow access, pick your input. Use headphones — see Audio In below.
Pan
Places a sound left/right in the stereo field. −1 = full left, 1 = full right.
EQ
3-band tone shaping. Cut Low to thin out a track, boost High for clarity, pull Mid down to make room for another track ("carving").
Compressor
Evens out volume swings. Thresh = level it kicks in at · Ratio = how hard it squeezes · Atk/Rel = how fast it reacts/lets go.
Chorus
Layers slightly-detuned copies for a thicker, shimmering sound. Rate/Depth = how the detune wobbles.
Limiter
A hard ceiling on loudness — put one right before Output to stop a mix from clipping. Thresh = the ceiling.

Module Categories

Every toolbar button and module card is color-coded by its role in the rack, so a glance tells you what a patch is made of:

Mixing Multiple Tracks

Build a mix
Add one Audio File module per stem, route each through its own Pan/EQ into a shared Gain or Compressor, then into one Output. Add a Limiter just before Output to keep the combined level in check.
+ Channel Strip
One click adds Pan → EQ → Compressor → Limiter in mixing order, spliced into whatever you already have, just before the Output. It joins your rack rather than standing up a second one beside it.
● Record — capturing what you play
Taps the master output, so it records the patch, the sequencer and the drums together, exactly as you hear them. The file is a 16-bit WAV: it opens in Logic, Ableton, Reaper, GarageBand and anything else, plays on every device, and loses nothing. Browsers only offer WebM here, which plays in a browser and is refused by most DAWs on import, so the recording is decoded and rewritten before it reaches your downloads. The trade is size — roughly 10 MB per stereo minute — which is the honest price of lossless and universal.
VU Meter
Every Output module shows a live level bar under its Master slider — green while there's headroom, amber as it gets hot, red near clipping. Pull the Master fader or add a Limiter upstream if it's pinned red.

Sequencer

Step Sequencer
Open with 🎼 Sequencer in the toolbar. It plays your patched sound — build a basic synth first (Oscillator → … → Output), press Start Audio, then hit Play. Click a step to turn it on or off; drag up or down on it to set its pitch. Set length (8/16/32 steps), BPM, swing, and gate length. The matching piano key lights up as each step fires. Patterns auto-save and reload.
Pitch moves by scale degree, not semitone
Set Key and a scale, and every pitch edit moves within that key — drag once and you land on the next note of the scale, not the next fret. Editing chromatically was the thing that made programming a melody here tedious, because most nudges landed outside the key and you fixed them by nudging again. Pick Chromatic from the scale menu if you want semitones back. Random respects your key too, so it gives you a usable starting point rather than a puzzle.
Velocity — how hard each step hits
Every step has a velocity strip beneath it: drag along it to set how hard that note plays, and the cell fills from the bottom to show it. On the drum rows there's no pitch to set, so dragging up and down on a drum cell sets its velocity directly — which is where ghost notes come from. A pattern where every hit is identical is the clearest giveaway of programmed music; see Groove & Timing for what to do with it. Arrow keys work too: ↑/↓ for pitch, ←/→ for velocity, once a step is focused.
Shaping each step (Decay/ADSR)
The sequencer has no envelope of its own — it plays through whatever's patched on the canvas. Add an ADSR module before Output and set a short Dec (decay) with low Sus (sustain) for plucky, percussive steps, or a longer Decay/higher Sustain for pads that bleed into the next step. It retriggers on every step automatically.
Balancing the drums against what you play
The drums bypass the patch on their way out, which is what lets them work before you have built a sound. It also meant they had one fixed level. The Mix pair at the right of the drum row fixes that: Drums is the kit's fader, Synth is everything you play. The Synth fader is the Output module's Master reached from down here, so the module's own slider moves with it and the two can never disagree. Each drum row also has its own fader under its name, so a hat can sit under a kick the way it would on any drum machine. Levels are remembered between visits; the per-voice faders are hidden on a phone, where the kit fader still does the balancing.
Drum Machine
Below the melodic grid, four drum rows — Kick, Snare, Hat, Clap — on the same clock and step count. Click cells to program a beat; each hit auditions as you click so you can build it by ear while stopped. Beat drops in a four-on-the-floor starting point to edit from — kick on every beat, snare on 2 and 4, and hats on eighths with alternating accents, because a flat hat line is what makes a beat sound typed in rather than played. The drums are synthesized and routed straight to the output, so they work without a patch on the canvas — you can program a beat before you've built a sound. Clear only wipes the melody; Clear Drums only wipes the beat.

⇅ Arpeggiator

What it does
Press ⇅ Arp, hold a chord, and the synth plays it one note at a time, in time. The notes are yours, the rhythm is the clock's. It runs on the same tempo as the sequencer, so the two lock together: program a beat, then hold chords over it. Keys, pads and MIDI all feed it; the sequencer and the guide bypass it, since they already know when their notes land.
The controls
Direction: Up, Down, Up & down, Random, or As played (the order you pressed the keys, which is how you write a melody with a chord). Rate is the note length — 1/8 for a groove, 1/16 for a run, triplets for a shuffle. Octaves repeats the chord that many octaves up, so a three-note chord over three octaves is a nine-note climb. Gate is how much of each step the note is held: short is staccato, long is legato, and with a Release on your ADSR the notes overlap.
Hold
With Hold on, the chord keeps playing after you let go, which frees your hands for the filter and the mixer. Play a new chord and it replaces the old one. Turning Hold off with no keys down stops the arpeggio.
Where it shines
The Arp and Chiptune presets switch it on with a sound made for it. Add an ADSR with a short Decay for a plucked arpeggio, and a Delay set to a dotted eighth (0.375 s at 120 BPM) so the echoes fall between the notes. A Mod Env on the filter cutoff is the difference between a run of notes and a run of plucks.

Presets — sixty sounds in six moods

The Presets row is six moods — Keys, Pads, Bass, Leads, Plucks & Arps, Texture & FX — and each opens a panel of sounds with a name and a line about when you'd want it: Warm Blanket, Choir of Ghosts, Harp in the Rain, Broken Radio. 🎲 Surprise me loads one you didn't choose, which is the fastest way to find a sound you'd never have reached for. Every preset is built from the same modules you can add by hand, so load one and read the rack: that is how it was made.

A few are lessons in one idea, and hovering their button says which. Pad and Strings are width and slowness: detuned saws, a sub, slow envelopes, chorus. Pluck and Trance Pluck are the filter envelope. E-Piano and FM Bell are FM at a harmonic ratio and an inharmonic one. Kalimba is an envelope with no sustain. Chiptune and Arp switch the arpeggiator on. Reese is wide detune under a driven filter. 808 is the Mod Env driving pitch. Dub Stab is a chord left to a long delay. Load one, then change one thing and listen for what moved.

♪ Guide — theory on the keys

What it is
Press ♪ Guide in the piano bar and the Theory page lands on the keyboard. Pick a root and a scale or mode, and every key that belongs lights up while the rest fall back — so when you don't know what to play, you play the lit ones and nothing is wrong. The amber key is the root: end phrases there and they sound finished. Names/Degrees switches the labels between note names and scale degrees, and ▶ Hear it runs the scale up and back through your patch.
Chords in key
The chords that live in a key, stacked in thirds off each degree, with their roman numerals — the same seven the Theory page builds. Tap one and its notes are coloured by their role: amber root, purple third, green fifth, yellow seventh. Three fingers on the coloured keys is the chord. The purple third is the note that decides major or minor; swap it and you swap the mood. Triads/7ths switches the family. Pentatonic and blues scales borrow the chords of their parent key.
Any chord
Any quality on any root — major, minor, 7ths, sixths, add9, ninths, half-diminished. Tap a chip to see and hear it. The same colours mean the same things on the Chord Voicings page, where Guitar ↗ takes the chord you're looking at and draws it on a neck, and Theory ↗ opens the scale on the Theory page.
It's a guide, not a lock
Dim keys still play. The guide only tells you which notes belong; whether to leave the scale is your call — and the moment you do it on purpose, you've learnt the thing the guide was for.

Touch Pads (phones & tablets)

Why they exist
Musical typing needs a computer keyboard, and a phone hasn't got one — which left the piano strip, whose keys are narrower than a fingertip. On a touch device the synth opens with pads instead: large multi-touch targets you can actually hit with a thumb. Switch between them any time with ◇ Pads.
Every pad is a right note
The grid is locked to a scale, so there is no wrong pad — pick a root and a scale from the two menus and play freely. It defaults to C Minor Pentatonic, which is the most forgiving scale there is. The amber pads are the root, so you always know where you are.
Chords and runs
Each row starts two scale steps above the row below it, so three pads stacked vertically are a chord — put three fingers down in a column. Sliding a finger across the grid retriggers each pad it crosses, which is how you play a run with one thumb. Hitting the top of a pad plays harder than the bottom.
Range
The /+ buttons move the whole grid by an octave, same as they do for the piano. Your root and scale are remembered between visits.

Musical Typing

Chromatic rows — the default
The simplest rule a keyboard can have: one long chromatic run, left to right, bottom row upwards. Every key on the four rows plays, every note appears exactly once, and neighbouring keys are neighbouring notes with no exceptions — no skips, no repeats, nothing to remember.
high1 2 3 4 5 6 7 8 9 0 - = q w e r t y u i o p [ ] a s d f g h j k l ; 'lowz x c v b n m , . /
45 keys, 45 semitones — three octaves and a major third, more than double what a two-row layout reaches. The rows join up seamlessly too: / to a, ' to q and ] to 1 are each one semitone, so the whole keyboard is a single ladder. Because no note is bound twice, every key on screen shows exactly one letter.
Piano shape — when you want to see chords
Pick Piano shape for the layout that mirrors an actual keyboard: two manuals an octave apart, letters as the white keys, the staggered row above as the black keys.
black1 2 3 4 5 6 7 8 9 0 - =white q w e r t y u i o p [ ]blacka s d f g h j k l ; 'white z x c v b n m , . /
Chord shapes look the way they look on a piano, which is its whole point — but the cost is that walking along one row skips notes: 5 to 6 jumps F♯ straight to G♯, because the G between them lives on the row below. That is correct as a piano and confusing as a keyboard, which is why it is no longer the default. Its E♯/B♯ slots (a, f, k, ', 1, 4, 8) play the white note they lean against, so nothing here is dead either.
Two rows
Logic Pro's Musical Typing, for anyone with the muscle memory: A W S E D F T G Y H U J up from C, continuing K O L P ; — a tenth in all. Much less range, but it leaves Z/X/C/V free as octave and velocity shortcuts.
Octave and velocity
/ shift the whole keyboard down or up an octave across the full MIDI range; / ride velocity. The /+ buttons beside the octave readout do the same thing with a mouse. On the Two rows layout, Z/X and C/V also work. Holding a note while you change octave is safe — the note you started is the note that stops.
Binding your own keys
Neither layout is fixed. Click ⌨ Remap, click a piano key, then press whatever key you want to play it — repeat for as many as you like, then Esc to finish. The layout menu switches to Custom and your bindings persist between visits, so you can flip out to a preset and back without losing them. Custom is your bindings layered over the current default rather than a frozen copy of it, so a key you never touched keeps following the standard layout and picks up any later improvement to it, while every key you did bind stays exactly as you set it. Right-click ⌨ Remap to reset. A custom binding on a key takes priority over that key's built-in shortcut.

Audio In — external gear through the rack

What it does
The Audio In module takes a live signal from anything your computer can hear and drops it into the patch as a source. An audio interface with a guitar, bass or hardware synth on it; a USB mic; a drum machine; a turntable; a phone on the desk. Everything downstream then treats it exactly like an oscillator — so the Filter, Delay, Reverb, Chorus, Distortion and Compressor all process your instrument, and the LFO can sweep the filter while you play it.
Setting it up
Add Audio In, click Enable, and allow access when the browser asks. The dropdown then lists every input on the machine — pick your interface rather than the built-in mic. Chrome or Edge, and an https:// page (this one is); browsers refuse microphone access over plain HTTP. Nothing is uploaded or recorded: the signal goes to your speakers and nowhere else.
Use headphones
Speakers into a live input is a feedback loop, and it builds to painful in about a second. Headphones remove the problem completely. There's a guard here that cuts the input level if the master output pins for a sustained second, but treat that as a net rather than a plan — it fires after the noise starts.
"It's live but I hear nothing"
Almost always an Envelope in the chain. An envelope is a note gate — it sits shut until a key is pressed — so a continuous signal passing through one is silent between keypresses. The module says so when it detects this and offers a one-click fix. (Deliberately routing an input through an envelope is a real technique: it lets you play a drone or a held pad in and out with the keyboard. It's just never what you want by accident.)
Latency and sound quality
Browser audio adds a few milliseconds on top of your interface's own buffer — fine for effects and for playing along, marginal for tight tracking. Echo cancellation, noise suppression and automatic gain are all switched off deliberately: they're voice-call processing, and on an instrument they gate off reverb tails, eat quiet passages and ride your dynamics away. If your input sounds thin or pumping, it's usually those being re-enabled by the OS rather than by this page — check your interface's own control panel.

MIDI — Controllers and DAWs

Play from a MIDI controller
Plug in a USB MIDI keyboard and allow MIDI access when Chrome prompts you. The MIDI: Connected badge confirms it. CC1 (mod wheel) sweeps filter cutoff; CC74 sweeps resonance, on every Filter module in the patch.
Send notes out to Logic Pro X
The MIDI Out dropdown sends every note this page plays — piano keys, MIDI controller passthrough, and the step sequencer — to an external MIDI port in real time, so Logic Pro X can record or play them through one of its own instruments. Requires three things: (1) Chrome or Edge — Web MIDI isn't supported in Safari or Firefox. (2) A virtual MIDI port — on macOS, open Audio MIDI Setup → Window → Show MIDI Studio, double-click IAC Driver, check Device is online, and make sure it has at least one port (the default "Bus 1" is fine). (3) A Logic Pro track listening on that port — create or select a Software Instrument track, open the track's input in the inspector, and set it to receive from the IAC bus you just enabled (or "All Inputs"). Once that's done, pick the IAC bus from the MIDI Out dropdown here — notes play through your local patch and get sent to Logic at the same time.

Building a Sound

Click these in order and the routing takes care of itself:

Sound Design Recipes