Dice pick the chords, the browser plays them back, and MIDI export gets the idea out. Keep what works, reroll the rest.
RNG Chords is for sketching progressions without opening a DAW. Choose guided or advanced generation, enter chords yourself, or mix both.
Choose an instrument focus and Easy, Color, or Tension complexity. Click Roll New Idea or Roll This Setup. Surprise Me also randomizes the musical setup and playback instrument.
Use Keep to pin a chord, Reroll to replace one slot, or Reroll Unlocked to change everything unpinned. Save versions in A, B, and C; select a filled slot to restore it. The app also restores the last session after a refresh.
Pick an instrument, tempo, and rhythm Feel, then use Play, Stop, and Loop. Preview individual chords or turn on theory labels. The manual builder also accepts symbols such as Cmaj7, Am7, D7, Gmaj7. Use Export MIDI to continue in another app.
| Key | Action |
|---|---|
Space |
Play or stop |
← / → |
Preview the neighboring chord |
Enter |
Replay the selected chord |
Browser audio may need an initial click before it can play. Musical judgment stays with you; a generated progression is a starting point.
The app uses Astro, React, Motion, Tone.js, and Bun.
bun install
bun run devbun run lint && bun run typecheck && bun test
bun run buildComponents, music logic, routes, and styles live under src/. Tests are in tests/; static assets are in public/.
Set SITE_URL in production so social metadata uses absolute URLs.