Staff View

Standard notation (grand staff) viewer for FeedBack, with MIDI-keyboard practice built in: live hit/miss scoring, hand isolation, and a note-by-note gated study mode. Rendered via alphaTab.

Renders any arrangement that carries notation data in the .sloppak chart format — no backend conversion, no extra HTTP request; the plugin builds an alphaTab.model.Score directly in JavaScript from the highway WebSocket stream.

How it works

• Auto-activates (matchesArrangement) when the loaded arrangement has has_notation: true.
• Accumulates notation_info / notation_measures over a per-instance WebSocket connection and calls AlphaTabApi.renderScore().
• No local synth — the host owns audio (OGG); enablePlayer:false drops alphaTab's own soundfont download. The cursor tracks the host's bundle.beats time stream (binary search → MIDI tick → boundsLookup.findBeat() → marker geometry).
• Options pill (v3 plugin-control slot / v2 #player-footer / splitscreen panel), sections persisted to localStorage:
  • NOTE DETECTION — master Detect on/off, and whether seeking clears miss-dots for the replayed region.
  • STUDY — note-by-note gated practice (see below).
  • HAND — RH/LH isolation on grand-staff scores, via alphaTab's native note colouring.
  • MIDI — device + channel picker (core midi-input domain), monitor-synth Sound + Volume.
  • LAYOUT / ZOOM — page vs. horizontal layout, 50–200% zoom.

Practice features

• MIDI input & scoring — connects through the core midi-input capability domain (mirrors plugins/keys_highway_3d); note-on/off is judged against the loaded score (±100ms) and reported through the core note-detection domain (register-provider / open-binding / reportHit/reportMiss) — staffview owns judgment, the domain only carries the observability event.
• Miss-dot overlay — a small dot marks any notehead whose hit window passed un-played; a monotonic sweep runs each frame, and a seek in either direction re-syncs without false-marking the jumped span.
• Core stats bridge — judged hits/misses feed core's live HUD, dashboard, and song_stats (note:hit/note:miss), including an injected RH/LH accuracy line on grand-staff scores. The scoreboard is repositioned to the bottom-right while staffview is showing notation.
• Monitor synth — a WebAudioFont-based synth plays back your MIDI keyboard (own CDN; keyboard tones aren't yet a core capability), with instrument/volume controls and a mixer fader.
• Study mode — the OGG pauses at each gate (a beat's required notes) and only resumes once they're all played correctly; wrong notes draw a clef-aware X at the pitch actually played. Study is unscored practice: it doesn't feed the live HUD or song_stats (a step-by-step run is always ~100% by construction), only the note-detection domain for observability. Optional metronome preroll count-in.
• Note explorer — alt-click (desktop) / double-tap (touch) a notehead for a pitch tooltip, without triggering seek.
• OGG loop — click-drag (or touch-drag) across the score sets a loop region via the platform's native setLoop() API, with a green overlay that mirrors loops set through the platform's own controls.

Install

Copy or symlink this directory into your FeedBack plugins/ folder:

plugins/
  staffview/    ← this repo

alphaTab is loaded from the jsDelivr CDN at runtime — no local build step needed.

Tests

Browser-free host-integration helpers have a node:test suite:

npm test

License

AGPL-3.0-only — see LICENSE.

Originally prototyped by Gionni; curated into the org for the piano/keys epic.