Add proper README with feature docs and synth reference

https://claude.ai/code/session_01GdFrFqAe9e2DaJ86jZPEZE

README.md

@@ -1 +1,61 @@
-# drum-rhythm-game
+# Drum Rhythm Game
+
+A browser-based drum rhythm game. Notes scroll down the screen and you hit the matching drum pad in time — like Rock Band, but it runs entirely in your browser with no server, no dependencies, no install. Just open `index.html`.
+
+Works with **keyboard**, **Wii Rock Band drum kit via USB**, or any gamepad.
+
+## How to Play
+
+1. Open `index.html` in Chrome or Edge
+2. Pick a genre and rhythm (or a classical piece)
+3. Click **Start**
+4. Hit the pads when notes reach the line:
+   - **F** = Red (Tom)
+   - **G** = Yellow (Snare)
+   - **H** = Blue (Hi-hat)
+   - **J** = Green (Tom)
+   - **Space** = Kick (Bass drum)
+
+## Features
+
+- **9 Genres**: Rock, Metal, Jazz, Hip Hop, Funk, Latin, Electronic, Country, Classical
+- **146 Rhythms**: 120 drum patterns + 26 classical orchestral pieces
+- **Classical Mode**: Synthesized orchestra plays automatically while you hit the melody notes on the pads. Choose between drum sounds or orchestral hit sounds.
+- **26 Classical Pieces**: Beethoven's 5th, Hall of the Mountain King, O Fortuna, Ride of the Valkyries, Toccata & Fugue, Bolero, Also Sprach Zarathustra (2001), The Blue Danube, Flight of the Bumblebee, Fur Elise, Canon in D, Ode to Joy, 1812 Overture, and more
+- **MP3 Jam Mode**: Load your own music and drum along freely
+- **Multiplayer**: Take turns on the same rhythm, scores compared at the end
+- **Pad Toggles**: Turn pads on/off to adjust difficulty — start with kick+snare, add more as you improve
+- **Leaderboard**: Scores saved locally with player name, accuracy, and streak
+- **Preview**: Hear any rhythm before playing
+- **Gamepad Support**: Wii Rock Band drums via USB, auto-detected
+
+## Synthesizer
+
+All sounds are generated in real-time using the Web Audio API — no audio files needed:
+
+| Sound | Method |
+|-------|--------|
+| Kick | Sine oscillator, 180Hz to 40Hz sweep |
+| Snare | Highpass noise burst + 180Hz tone |
+| Hi-hat | Highpass noise burst, very short |
+| Toms | Sine oscillator pitch sweep |
+| Strings | Sawtooth oscillator + lowpass filter |
+| Brass | Square oscillator + lowpass filter |
+| Woodwind | Triangle oscillator |
+| Bass | Sine oscillator, low frequency |
+| Timpani | Sine frequency sweep |
+| Choir | Multiple detuned sine oscillators |
+
+## Tech
+
+- Pure vanilla JavaScript — no libraries, no build step, no server
+- Single `index.html` file
+- Web Audio API for all sound synthesis
+- Canvas 2D for the note highway
+- Gamepad API for drum kit input
+- localStorage for score persistence
+- Works on Windows, Linux, and Mac
+
+## License
+
+[MIT](LICENSE)