🎹 MIDI Editor - Web-based Singing MIDI Editor

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A full-featured web MIDI editor for singing voice preprocess. It supports real-time drag editing of MIDI notes, lyric editing, audio waveform alignment, and importing/exporting MIDI files with lyrics.

✨ Features

🎼 Piano Roll Editing

• Visual note editing: Full range from C1 to C8 with intuitive piano key layout
• Drag operations:
  • Move notes: drag note blocks to adjust position and pitch
  • Resize start: drag the left edge to adjust start time
  • Resize end: drag the right edge to adjust end time
• Quick pitch adjust:
  • Command/Ctrl + Up/Down to nudge selected note pitch
  • Use the Transpose control in the toolbar to shift all notes at once
• Double-click to add: Add new notes quickly in empty areas
• Piano key preview: Click a key on the left to audition the pitch

🔍 Zoom & Navigation

• Horizontal zoom
• Vertical zoom
• Dynamic snapping: finer snap granularity at higher zoom (min 0.01s)
• Auto scroll: keep the playhead visible during playback

📝 Lyric Editing

• Inline editing: edit lyrics for each note in the side list
• Batch fill: enter lyrics and auto-fill notes in order
• Fill from selection: start batch fill from the currently selected note
• Precise fields: edit PITCH, START, and END directly
• Confirm edits: press Enter or click ✓ to confirm, avoiding accidental changes

🎵 Audio Alignment

• Waveform display: import audio to display waveform, synced with the MIDI timeline
• Formats: MP3, WAV, OGG, FLAC, M4A, AAC
• Sync playback: play audio and MIDI together with independent volume control
• Click to seek: click waveform or timeline to seek

⚠️ Overlap Detection

• Visual highlight: overlapping notes blink in red
• One-click fix: remove all overlaps automatically

📥 Import & Export

• MIDI import: parse standard MIDI files with automatic lyric metadata extraction
• MIDI export: export MIDI files with lyric information

🎨 UI & UX

• Theme toggle: light and dark modes
• Responsive layout: adapts to window size
• SVG grid: cross-browser grid rendering
• Status feedback: real-time state and error tips

🚀 Quick Start

Requirements

• Node.js 18+
• npm or yarn

Install

# Install dependencies
npm install

# Start dev server
npm run dev

# Expose to LAN
npm run dev -- --host 0.0.0.0

Build

# Build for production
npm run build

# Preview build
npm run preview

📖 Usage

Basic Workflow

1. Import MIDI: click Import MIDI and select a .mid file
2. Edit notes: drag notes in the piano roll to adjust time and pitch
3. Add lyrics: edit lyrics in the right-side list, or use batch fill
4. Align audio (optional): import reference audio for side-by-side editing
5. Export: click Export MIDI to save

Shortcuts

Playback Controls

🛠 Tech Stack

• Frontend: React 19 + TypeScript
• Build: Vite 7
• State: Zustand
• Audio: Tone.js
• Waveform: WaveSurfer.js
• MIDI: @tonejs/midi
• Styles: CSS with custom variables

📁 Project Structure

.
├── eslint.config.js
├── index.html
├── package.json
├── postcss.config.js
├── README.md
├── README_CN.md
├── tailwind.config.js
├── tsconfig.app.json
├── tsconfig.json
├── tsconfig.node.json
├── vite.config.ts
├── public/
└── src/
    ├── App.css              # Main styles (theme variables, layout, components)
    ├── App.tsx               # Main app component (transport, import/export, transpose)
    ├── constants.ts          # Constants (grid width, row height, pitch range)
    ├── i18n.ts               # Internationalization (zh/en translations, smart lyric tokenizer)
    ├── index.css             # Global styles (Tailwind, root font, theme gradients)
    ├── main.tsx              # React entry point
    ├── types.ts              # Type definitions (NoteEvent, TimeSignature, etc.)
    ├── components/
    │   ├── AudioTrack.tsx    # Audio waveform display component
    │   ├── LyricTable.tsx    # Lyric editing table component
    │   └── PianoRoll.tsx     # Piano roll editor component
    ├── lib/
    │   └── midi.ts           # MIDI import/export utilities (UTF-8 lyric encoding)
    └── store/
        └── useMidiStore.ts   # Zustand state management