minichord Sound Lab

A free companion app for the minichord. Watch your playing light up live, learn what every setting does in plain language, and shape the instrument's sound. It runs in your web browser, with or without a minichord plugged in.

Try it now

Open Sound Lab in your browser →

Nothing to install. It opens like any web page. If you have a minichord, plug it into your computer with a USB cable and click Connect.

What it is

The minichord packs a full synthesizer into a pocket-sized instrument, but most of its settings hide behind three knobs. Sound Lab lays them all out on screen, explains each one, and draws live graphs of what you're shaping. Plug in over USB and you hear every change on the instrument as you make it.

No minichord? Everything still works in learning mode. You can click around, read the explanations, and even preview chords on the Play screen, all offline.

Get your own copy

There are two ways to use Sound Lab.

Use it online

Open the link above (once it's live) and you're ready. Bookmark the page if you'd like to come back to it. It works on any modern computer.

Download a copy that works offline

Sound Lab is one small, self-contained folder. You can keep a copy on your own computer and open it any time, even with no internet.

If you've never used GitHub before, here's the whole process:

1. Open the project page: https://github.com/MinichordDrawn/minichord-soundlab
2. Click the green Code button near the top right.
3. Choose Download ZIP. A .zip file lands in your Downloads.
4. Unzip it (double-click on a Mac, or right-click and "Extract All" on Windows).
5. Open the unzipped folder and double-click index.html. It opens in your web browser.
6. Bookmark the tab so it's one click away next time.

That's the whole thing. No git, no command line, no setup. To connect a minichord, use Chrome or Edge: they support the browser feature that talks to the device. Firefox works too, but it asks for permission first. Safari can run the app in learning mode but can't connect the device.

Using it with a minichord

1. Plug the minichord into your computer with a USB cable.
2. Click Connect in the Device card at the top left.
3. Play. The on-screen buttons and harp strings light up as you press and strum, and the chord you're holding is named for you.

Every control you move is sent to the instrument right away, so you hear edits as you drag. Use Save to bank to store a sound on the device, and the ● Record MIDI button above the Play screen to capture what you play into a standard .mid file any music app can open.

Using it without a minichord

You don't need the device to explore. In learning mode every control, graph and explanation works, and the Play screen previews a chord when you click a button. It's a full tour of what the instrument can do.

How the live mirror works (and why it sometimes guesses)

Here's the part that surprises people. The minichord only sends the notes you play over USB, never which button or string you touched. So Sound Lab works backwards: it knows your current settings, works out the exact notes each button and string would make, and matches the incoming notes against that to light the right ones.

Most of the time it's spot on. Now and then it has to make a best guess, because two different chords can sound the same notes, or because a knob can change a setting without reporting it. When it's unsure it picks the most likely reading and corrects itself as you keep playing. None of this touches your sound. It only changes what lights up on screen.

What you can do

• Play is a live mirror of the instrument. Chord buttons and harp strings light up as you play, the current chord is named for you, and the rhythm sequencer's playhead sweeps along in time.
• Customize opens every setting the firmware has, far more than the three knobs reach, grouped into sections (chord voice, harp voice, space, MIDI, knobs). Each one has a plain-language explanation and a live graph, and a built-in Sound Profiler describes any patch in words.
• Presets let you browse and load ready-made sounds, save your own, and copy settings to and from the clipboard to share.
• Triggers change a setting or load a preset automatically when you play a certain chord, pluck a string, or press a key.
• Randomize rolls a fresh sound with one click, with guardrails that keep it musical.
• Pin your favourite controls into the Play screen so they're always at hand.
• Click any setting's name or underlined word for a definition in plain English.

Accessibility & comfort

Sound Lab is built to work for everyone, not just power users. From the ⚙ and ♿ buttons at the top right you can set:

• Text size, from small to extra large.
• Reduce motion, to switch off animations and fades (or follow your system setting).
• High contrast, for stronger edges and brighter text.
• Larger controls, for bigger buttons, sliders and click targets.
• Explanation depth: Beginner spells everything out inline, Advanced keeps it tight.

The whole app is keyboard operable, with shortcuts you can customize (press ? any time for the list). It announces things like connecting and saving to screen readers, and a skip link jumps straight to the main content. It runs offline, needs no account, and nothing you do ever leaves your computer.

Tips & troubleshooting

• The device won't connect. Use Chrome or Edge, and check that the minichord is plugged in with a USB data cable (some cables only carry power). Firefox shows a permission prompt first.
• A steady buzz when it's plugged into a computer. That's almost always a ground loop, not a fault. The About screen inside the app has a card explaining the easy fixes (a ground-loop isolator, headphones, or running on battery).
• I moved a knob and nothing changed. A few settings (the ones that change which notes the buttons and strings play) only take effect on the next chord press or strum. Play a note and it catches up.
• The harp doesn't light up on the Play screen. Turn off "single port mode" in the MIDI settings. The live mirror needs the harp and chords on separate ports.

Free & private

Sound Lab is made by the minichord community, in the same spirit as the instrument. It's free and always will be. It runs entirely in your browser, and nothing you play or edit ever leaves your computer.

The minichord

The minichord is an open-source instrument by Benjamin Poilvé. Sound Lab is an unofficial, community-made companion for it.

• minichord.com, the project's home and documentation.
• The user manual, how to play, charge and care for the instrument.
• The community forum, to share music, presets and questions.
• github.com/BenjaminPoilve/minichord, the hardware and firmware sources.

For developers

Sound Lab is plain HTML, CSS and JavaScript. There's no build step, no framework, and nothing to ship beyond the folder itself. Open index.html and it runs.

Project map

Everything Sound Lab knows about the firmware's behaviour is documented, with citations, in MINICHORD-REFERENCE.md.

Testing & linting

The inference engine (devicemap.js) has a deterministic replay harness:

cd __harness__
node run.js > out.txt && diff out.txt golden.txt   # any diff is a behaviour change

See __harness__/README.md for details. The rest of the app is verified by hand in the browser. It's a UI.

Static checks guard correctness without imposing formatting. The dense data tables and aligned comments are deliberate:

npm install        # dev tooling only; the app itself has no dependencies
npm run check      # everything below in one go
npm run lint       # eslint (JS correctness + per-token style)
npm run lint:css   # stylelint
npm run lint:html  # html-validate
npm run test       # devicemap harness vs golden transcript
npm run smoke      # headless Chrome boot test (needs Chrome installed)

License

CC BY-NC 4.0: free to use, share and adapt with attribution, but not commercially. The same license family as the minichord hardware itself. Sound Lab is and will always be free.