Shed Web

A browser-based jazz ear-training trainer, carrying over the theory core, exercise design and pedagogy of Shed — originally built for the M-VAVE FM-1 synthesizer — to a standalone web app anyone can use, no hardware required.

Nine exercises: functional degree, chord quality, melodic interval, harmonic interval, dominant tension, arpeggio, scale/mode, bass movement and melodic dictation — plus Vamp mode's ear rounds. Sessions adapt their difficulty to your streak and use spaced repetition to resurface what you keep missing, across all 12 keys. Vamp mode loops a chord progression (bass + comping, 5 named vamps) while you improvise over it on an on-screen piano, with chord/scale-tone key guidance (Arpeggio/Scale/Guide/None views) and an "ear" round that quizzes you on what's sounding.

Try it live: shed-web.vercel.app

Stack

• React + TypeScript + Vite, no backend — everything runs client-side.
• src/core/ is a straight TypeScript port of fm1_open's app/shed/theory.c, exercises.c and progress.c (GPL-3.0-only WITH GPL-3.0-linking-exception) — same chord/scale tables, same question generator, same adaptive-difficulty and spaced-repetition logic, same deterministic RNG, same vamp data. tests/ mirrors the original's host test suite.
• src/audio/synth.ts is a small Web Audio synth (not a port of anything — there's no DX7 engine in a browser) that keeps the original's voicing choices (rootless piano voicings, piano/bass registers) so a chord sounds the way the device played it. src/audio/vampSequencer.ts is a look-ahead scheduler that loops a vamp indefinitely (the original's player.c instead scheduled only the current + next step, working around the firmware's fixed-size event queue — a browser has no such constraint).
• src/app/ is the UI: a menu, a per-exercise question screen (an on-screen piano for note/sequence answers, a choice grid for chord/tension/scale picks), feedback, a session summary, and Vamp mode's own screen (polyphonic piano, view switcher, ear round).

Develop

npm install
npm run dev        # http://localhost:5173
npm test            # core logic test suite (vitest)
npm run build        # production build to dist/

License

GNU GPL v3.0. The ported core (src/core/) is a derivative work of app/shed/theory.c, exercises.c and progress.c from the upstream fm1_open / Shed project, originally licensed GPL-3.0-only WITH GPL-3.0-linking-exception; that exception existed for linking against the FM-1's proprietary binary SDK, which this project has no dependency on, so it's distributed under plain GPL-3.0-only. The rest (audio synth, UI) is original to this project, under the same license.