MIDI Editor

MIDI Editor

Built-in editor with four specialised modes sharing a transport, channel panel, undo/redo stack, and backend persistence. Architecture and extension points live in docs/MIDI_EDITOR.md.

Modes

Mode	What it edits	Source
Piano Roll	Notes on 16 channels, velocity, snap grid 1/1 → 1/16	public/js/features/midi-editor/
Tablature	String instruments (19 tunings), bidirectional MIDI ↔ tab	See Advanced-Topics
Drums	Grid, GM drum map (notes 35–81)	Drum grid renderer
Wind	Articulation, breath dynamics	Wind melody renderer

Toolbar

Save, Save As, rename, undo / redo, copy / paste / delete, select-all, snap grid, horizontal & vertical zoom, transport (play / pause / stop), auto-assign routing, channel-settings popover, preview-source toggle (GM ↔ routed devices).

CC and Automation

Editable controllers: CC 1, 2, 5, 7, 10, 11, 74, 76, 77, 78, 91, 93. Plus pitch bend, channel & poly aftertouch, velocity curves, and tempo automation. Curve drawing tools cover linear, exponential, logarithmic and sine shapes.

Reserved CC ranges (e.g. hand position on CC 23/24) are documented in docs/MIDI_CC_INSTRUMENT_CONTROLS.md.

Keyboard Shortcuts

Key	Action
Ctrl/Cmd + S	Save
Ctrl/Cmd + Z	Undo
Ctrl/Cmd + Y or Ctrl + Shift + Z	Redo
Ctrl/Cmd + C / V	Copy / paste selected notes
Ctrl/Cmd + A	Select all
Delete / Backspace	Delete selected notes (or CC / velocity points if that section is open)
Space	Play / pause
Escape	Close dialog or editor

Common Features

• Built-in synthesizer preview with 7 soundfonts.
• Per-channel routing to connected devices, with playable-note highlighting (notes outside an instrument's range are dimmed).
• Cursor repositioning during playback pause.
• Touch mode for tablets — separate Move / Add / Resize buttons replace gesture overloads.

User Preferences

Persisted in localStorage under gmboop_settings:

• touchMode
• keyboardPlaybackFeedback
• dragPlaybackFeedback

Extending the Editor

The editor uses a renderer-per-mode design. To add a mode, register a renderer in the editor entry point and provide:

• A converter (model ↔ visual representation)
• Toolbar actions
• Keyboard shortcuts (via the shared shortcut registry)
• Optional touch-mode controls

See the architecture and extension points in docs/MIDI_EDITOR.md.