Add LilyPond transcriber documentation to README

README.md

@@ -176,3 +176,42 @@ Messages sent to `/freq` with: voice number (int), frequency (float).
 ### Test Receiver
 
 For debugging, run `python src/test_receiver.py` in a separate terminal.
+
+## LilyPond Transcriber
+
+**⚠️ IN DEVELOPMENT** - This feature is experimental and may change.
+
+The LilyPond transcriber converts generated chord data into music notation.
+
+### Usage
+
+```bash
+# Generate path first, then transcribe
+python compact_sets.py --dims 4 --chord-size 4 --symdiff-min 4 --symdiff-max 4 --max-path 200 --target-register 3 --weight-target-register 10
+python compact_sets.py --transcribe
+
+# Custom input and output name
+python compact_sets.py --transcribe output/output_chords.json my_piece
+
+# From any chords file
+python compact_sets.py --transcribe path/to/chords.json
+```
+
+### Output
+
+Generated files go to `lilypond/{name}/`:
+- `score_template.ly` - Template file
+- `{name}.ly` - Full score
+- `{name}.pdf` - PDF output
+- `includes/part_I.ly` through `part_IV.ly` - Individual voice parts
+
+### What It Generates
+
+The transcriber produces:
+- **4 voice parts** (I, II, III, IV) with automatic clef changes
+- **Cent deviation markings** showing how far each pitch is from equal temperament
+- **Dimension markup** showing which prime dimension changed and by how much (e.g., "III 5↑" = 5th dimension up from voice III)
+
+### Requirements
+
+- [LilyPond](http://lilypond.org/) must be installed and in PATH