From MIDI to mastery. Turn any MIDI file into an interactive piano-learning experience.
Orfeo is a free, open-source desktop app that turns MIDI files into an interactive piano lesson: notes fall onto a virtual keyboard in real time, keys light up as they play, and you can slow down, loop, transpose, and explore any passage at your own pace. Real-time chord detection, hand-coloured keys, interactive chord and scale explorers, a full mixer, and per-note editing — with a piano roll that looks like it was built this decade.
It's not a game — no scoring, no streaks, no subscription. No account, no telemetry; MIDI files are processed entirely on your device.
Image ·
readme/hero.png· 1600×1000 · Orfeo mid-playback: falling notes on the 88-key keyboard, keys lit in track colours, the live chord name above.
- Import
.mid/.midi, plus MusicXML, Guitar Pro, Capella, and karaoke.kar(converted automatically) - Falling-note piano roll onto a 61 / 73 / 88-key keyboard, colour-coded per track, pixel-aligned to each key
- Tempo control — slow down or speed up without changing pitch; long-press the BPM arrows to glide to a target
- Change key — transpose the whole piece by semitones
- Loop region — draw a loop directly on the waterfall and drill any section
- Metronome — follows the file's embedded tempo map through mid-song changes; right-click for volume and count-in
- Count-in — 1–4 bars of clicks before the music starts, at the song's real tempo, leading straight into the first note
- Tap Tempo — fix songs whose bar lines and metronome don't match the music: tap along on Space or a MIDI key, and Orfeo lines your beat up with the song's own drums and bass, remembers it for that song, and never touches the file
- Tempo warnings — optional marks in the Library and the top bar for songs whose bar lines and metronome don't match the music's beat
- Tracks panel & Console Mixer — mute, solo, recolour, show/hide tracks; per-channel volume, pan, chorus, reverb with live VU meters (saved into the file on close); master Tone and Compressor
- Focus Mode — narrow instantly to keys, bass, and drums
- Presentation Mode (
F11) — distraction-free view of just the roll and keyboard
- Click or drag to play; drag across keys for glissando
- Docked or floating — a draggable, resizable panel for multi-window setups
- Key highlighting in track colour, with the chord name shown live above
- Automated hand assignment — notes colour-code by which hand plays them, in Practice (moving split line) or Performance (per-note tags) mode, with optional colourblind-friendly L/R badges
- Hardware MIDI input — play along on a real keyboard with true sustain and multi-device support
- Chord Explorer — browse and audition any chord in any key; filter by hand span or note count; cycle inversions; play progressions in seven voicing styles
- Scale Explorer — interactive Circle of Fifths; ten scale types, each with its diatonic chords and Roman numerals
- Real-time chord detection with three tracking modes (Auto, Harmony, Follow Instrument)
- Chord Prompter — a lead-sheet-style past / current / next readout synced to playback
- Chord Transcription (beta) — generate a printable chord chart PDF for any file
- Lock-a-Chord —
Shift+click any 3+ keys to build and lock a chord, then cycle inversions
- MIDI Playback Editor — exclude, rename, recolour, reassign instrument,
merge, and split-hands tracks; saves as a new
_ORFEO_vN.midwithout touching the original - Note Editor — move, resize, add, delete, and re-velocity individual notes on the roll, with marquee / lasso / pen tools and full undo/redo
- MIDI library — browse a folder, star favourites, fuzzy-search, auto-refresh
- Edit history embedded in the file — travels with the
.midanywhere, survives reinstalls
- Hit effects — seven optional particle animations where notes strike the keyboard (glow bloom, ripple ring, particle burst, smoke plume, colour aura, starburst nova, comet trail), with custom colour and a real bloom filter
- Master volume — a physical-feeling toolbar knob, persists across sessions
- Two engines — General MIDI (instant, no download) or Samples (SpessaSynth + downloadable SF2/SF3 soundfonts, GeneralUser GS by default) for far richer sound
- Setup — the everyday switches (sound engine, Focus mode, Tap Tempo, note names, key range, zoom…) in the left panel, each with a one-line explanation
- Settings window (
Ctrl,) — every setting in eight groups with full descriptions, a search box, and a link to the matching page of the online manual
Full walkthrough of every feature: docs/HOW_TO_USE.md.
Grab the latest build from the Releases page:
| File | Use |
|---|---|
Orfeo Setup <version>.exe | Standard Windows installer — Start Menu shortcut, automatic updates |
Orfeo-<version>-portable.exe | Portable — no installation, runs from anywhere, manual updates |
Not sure which, or want to know how they differ (auto-updates, where settings live)? See docs/INSTALLATION.md.
| Document | What's in it |
|---|---|
| How to Use | The complete guide — Play, Edit, Practice, Manage files, Extras |
| Shortcuts | Every keyboard and mouse gesture |
| Installation | Installer vs. portable, updates, where data lives |
| Architecture | How Orfeo is built and why |
| Changelog | Technical release history |
| Contributing | Build from source, cut a release |
git clone https://github.com/Squarebow/Orfeo.git
cd Orfeo
npm install
npm run devRequires Node.js 20 LTS or newer. Full build and release instructions, including macOS/Linux, are in docs/CONTRIBUTING.md.
Is Orfeo free?
Yes — completely free and open source. No subscription, no paywalled features, no account.
Does it need an account or an internet connection?
No account, no login, no telemetry — and no internet connection is needed to play, practise or edit. MIDI files are processed entirely on your device, and both sound engines work offline: the Samples engine's default sound set (GeneralUser GS) ships inside the installer.
Orfeo only goes online when you ask it to, or to check for updates:
- Extra sound sets (FluidR3 GM ~142 MB, MuseScore General ~38 MB) are not
in the installer; each is downloaded once, only when you press its download
button in Settings → Audio, and kept in
%APPDATA%\Orfeo\soundfonts\(your own imported.sf2/.sf3files go there too). - Updates: the installed version checks GitHub for a new release when it starts; the portable version only shows a link. Offline, this simply doesn't happen.
- Links (How to Use, GitHub) open in your web browser.
What platforms does Orfeo run on?
Windows 10/11 today, with an installer and a portable build. Orfeo is built on Electron, so macOS and Linux builds are possible and community-buildable — see CONTRIBUTING.md — there just aren't official builds for those platforms yet.
Does Orfeo support Finale, Sibelius, or MuseScore files?
Not their native formats directly — but all three export MusicXML, which Orfeo
imports and converts to MIDI automatically. Guitar Pro, Capella, and karaoke
.kar files are supported natively too.
What MIDI files work best?
Real, human-performed files with natural rubato and mid-song tempo changes — Orfeo tracks the tempo map properly instead of assuming a flat click. Cleanly quantized files work great too. Messy downloads can be cleaned up with the Playback and Note editors without touching the original.
Before Synthesia there was Rondo — a lovely, Mac-only MIDI learning app with a scrolling piano roll, tempo slowdown, and track filtering. Development stopped and it no longer runs on modern macOS. The alternative that filled the gap became expensive and gamified, and hasn't meaningfully modernized in years.
Orfeo picks up Rondo's idea, rebuilt from scratch as an actively maintained, cross-platform-capable app with one goal: make the music itself — not the app around it — the focus. Free forever, no gamification, real rubato support, open source, and a modern interface.
Inspired by Rondo (RIP).
GPL-3.0-or-later © SquareBow — see LICENSE.md. Bundles GSAP under a separate additional-permission grant; see the license file and THIRD_PARTY_LICENSES.md.