# MUSIC-009 — Save / Load Music Projects

## Project format

MusicOS projects use a portable JSON format with:

- format version
- project ID
- title
- author
- created/updated timestamps
- tempo
- time signature
- duration
- tracks
- clips
- sections
- musical notes
- instrument assignments
- mute/solo state

## Example

```json
{
  "format": "musicos-project",
  "version": "0.1",
  "title": "My Cinema Theme",
  "tempo": 90,
  "timeSignature": "4/4",
  "tracks": [],
  "sections": [],
  "notes": []
}
```

## Design rules

1. The JSON file is the source project representation.
2. Audio rendering is separate from project storage.
3. Projects must remain editable after reload.
4. The format should be extensible without breaking older projects.
5. No third-party cloud service is required.

## V0.1 operations

- New project
- Save JSON
- Save As JSON
- Load JSON
- Import project
- Export project
- Browser local backup
- Project validation
- Version metadata

Future versions can add MIDI import/export, audio stems, thumbnails and CinemaOS project linking.