Notationfor Mac

Write scores from the keyboard.

🔒 Unsigned by Apple: the first open is blocked; System Settings > Privacy & Security > Open Anyway, once. fact

🎼 What Phase 0 does

Each line comes from the project's progress log fact

⌨️ Note entry from the keyboard: Sibelius keypad layout: 1 to 6 pick 32nd to whole, 7 8 9 natural, sharp, flat, 0 rest, . dot, Enter tie. A key reaches the screen in 32.5 ms (median, end-to-end test)
🧭 One input path: Every key, toolbar button, command palette row and panel edit runs the same named command, so menus and shortcuts never disagree
🎹 Chord symbols and lyrics: Typed in place under the caret; an unknown chord like "Bob's weird chord" is kept and flagged
🧱 Structure: Time and key signatures, rehearsal marks, repeats, endings, D.S. al Coda, a second voice, triplets
📐 Symbols never collide: A symbol lands on the side of the staff you click, moves clear of notes and lyrics, and lines up with its kind across the system
📂 Files: MusicXML in and out, its own .nscore format, autosave, PDF export; MuseScore 4 opens the exports
🖥️ Desktop app: Notation.app with native File, Edit, View, Play and Window menus; it starts its own notation host and stops it on quit
🤖 Claude can write in it: An MCP server named notation edits the open score through the same commands, proven by a headless Claude session writing a counter-line
🔊 Playback: Plays through the GeneralUser GS soundfont, served by the host

Found in the Phase 0 review; screenshots are headless captures of the app at 1280×800 fact

Before: Both went through the command palette: 20 keys for the barline, 25 for the tempo
After: Barline in 1 key; "Medium swing 132" in 19
Keys: ⌘⌥B final barline · ⌘⌥T tempo field

Before: The field said only "Chord"
After: "Chord · bar 5 beat 2", updating with Space and Tab; the lyric field does the same
Key: ⌘K

Before: A MusicXML tune in F with no key signature opened in C
After: Import reads the chords and notes, sets one flat, and the panel says "F major (inferred)"
Key: None, it runs on import

The editor build under /app/ on this site carries no .sf3 file fact

Before: Light only
After: Graphite page with light ink; View > Theme offers System, Light, Dark; exports stay light
Key: ⌘⇧D

Counted from the command keys by the exit test on Alexander's Ragtime Band, typed file paths excluded; not measured in Sibelius fact

🎹 Sibelius for the same job: 89 keys and 16 clicks, modeled from its documentation, not measured inference

⌨️ Dvorak: ⌘⌥ shortcuts read the physical key, proven by unit tests with synthetic layouts, not yet on a real Dvorak keyboard inference
🍎 Theme menu: present in the desktop app, never clicked in a test fact
🔁 Sibelius round trip: not run fact
🔈 MIDI out: not yet heard through a MIDI device fact
🎵 Tune 71: not exported; no MusicXML of it exists fact
🔤 PDF text fonts: still embedded as Type 3 fact

The editor is a client of the notation host on your Mac; without the host it cannot open a score fact

Steps

Clone therecordingclub/trc-notation (private) and install with pnpm install inside app
Start the host, which builds the editor and serves it:
```
cd app && pnpm start
```
Open http://127.0.0.1:7460/ on the same Mac
Or skip all of this: open Notation.app, which starts its own host

🌐 The same editor build is on this site at /app/; it shows a banner and waits, because no host runs on a web server fact