Add comprehensive README with configs, usage, attribution

README.md

@@ -12,16 +12,16 @@ tags:
 - musicxml
 - lilypond
 size_categories:
-- 1K<n<10K
+- 10K<n<100K
 configs:
-- config_name: default
+- config_name: pages_transcribed
   data_files:
   - split: dev
-    path: data/dev-*
+    path: pages_transcribed/dev-*
   - split: test
-    path: data/test-*
+    path: pages_transcribed/test-*
   - split: train
-    path: data/train-*
+    path: pages_transcribed/train-*
 - config_name: pages
   data_files:
   - split: dev
@@ -30,14 +30,6 @@ configs:
     path: pages/test-*
   - split: train
     path: pages/train-*
-- config_name: pages_transcribed
-  data_files:
-  - split: dev
-    path: pages_transcribed/dev-*
-  - split: test
-    path: pages_transcribed/test-*
-  - split: train
-    path: pages_transcribed/train-*
 - config_name: scores
   data_files:
   - split: train
@@ -47,10 +39,8 @@ configs:
   - split: dev
     path: scores/dev-*
 dataset_info:
-- config_name: pages
+- config_name: pages_transcribed
   features:
-  - name: image
-    dtype: image
   - name: score_id
     dtype: string
   - name: corpus
@@ -59,6 +49,14 @@ dataset_info:
     dtype: int64
   - name: n_pages
     dtype: int64
+  - name: bar_start
+    dtype: int64
+  - name: bar_end
+    dtype: int64
+  - name: musicxml
+    dtype: string
+  - name: image
+    dtype: image
   - name: composer
     dtype: string
   - name: opus
@@ -67,18 +65,20 @@ dataset_info:
     dtype: string
   splits:
   - name: dev
-    num_bytes: 27048193
-    num_examples: 339
+    num_bytes: 81654956
+    num_examples: 329
   - name: test
-    num_bytes: 31131909
-    num_examples: 478
+    num_bytes: 89237566
+    num_examples: 455
   - name: train
-    num_bytes: 1181562028
-    num_examples: 16225
-  download_size: 977001946
-  dataset_size: 1239742130
-- config_name: pages_transcribed
+    num_bytes: 3160588563
+    num_examples: 14129
+  download_size: 1135929995
+  dataset_size: 3331481085
+- config_name: pages
   features:
+  - name: image
+    dtype: image
   - name: score_id
     dtype: string
   - name: corpus
@@ -87,14 +87,6 @@ dataset_info:
     dtype: int64
   - name: n_pages
     dtype: int64
-  - name: bar_start
-    dtype: int64
-  - name: bar_end
-    dtype: int64
-  - name: musicxml
-    dtype: string
-  - name: image
-    dtype: image
   - name: composer
     dtype: string
   - name: opus
@@ -103,16 +95,16 @@ dataset_info:
     dtype: string
   splits:
   - name: dev
-    num_bytes: 81654956
-    num_examples: 329
+    num_bytes: 27048193
+    num_examples: 339
   - name: test
-    num_bytes: 89237566
-    num_examples: 455
+    num_bytes: 31131909
+    num_examples: 478
   - name: train
-    num_bytes: 3160588563
-    num_examples: 14129
-  download_size: 1135929995
-  dataset_size: 3331481085
+    num_bytes: 1181562028
+    num_examples: 16225
+  download_size: 977001946
+  dataset_size: 1239742130
 - config_name: scores
   features:
   - name: score_id
@@ -147,51 +139,201 @@ dataset_info:
   dataset_size: 1578308461
 ---
 
-# OpenScore — Full-Page Score Images
+# zzsi/openscore — OpenScore Sheet Music Pages
 
-Full-page score images rendered from the [OpenScore](https://github.com/OpenScore)
-corpora via [LilyPond](https://lilypond.org), paired with source MusicXML.
+Rendered sheet music pages from three open-score corpora, paired with
+per-page MusicXML ground truth. Intended for optical music recognition (OMR)
+research and supervised fine-tuning of vision-language models.
+
+Images are rendered from source MusicXML via
+[LilyPond](https://lilypond.org) (Emmentaler font). Per-page MusicXML is
+extracted by parsing bar numbers from the rendered SVGs and slicing the source
+score with [music21](https://web.mit.edu/music21/).
+
+---
 
 ## Corpora
 
-| Corpus | Scores | Staves/system | Source |
-|--------|--------|---------------|--------|
-| Lieder | ~1,460 | 3 (voice + piano) | [OpenScore/Lieder](https://github.com/OpenScore/Lieder) |
-| Quartets | ~122 | 4 (violin I/II + viola + cello) | [OpenScore/StringQuartets](https://github.com/OpenScore/StringQuartets) |
-| Orchestra | ~94 movements | 10–20+ (full orchestra) | [MarkGotham/Hauptstimme](https://github.com/MarkGotham/Hauptstimme) |
+| Corpus | Scores | Instrumentation | Source |
+|--------|-------:|-----------------|--------|
+| `lieder` | ~1,460 | Voice + piano (3 staves) | [OpenScore/Lieder](https://github.com/OpenScore/Lieder) |
+| `quartets` | ~122 | String quartet (4 staves) | [OpenScore/StringQuartets](https://github.com/OpenScore/StringQuartets) |
+| `orchestra` | ~94 movements | Full orchestra (10–20+ staves) | [MarkGotham/Hauptstimme](https://github.com/MarkGotham/Hauptstimme) |
+
+---
 
-## Format
+## Configs
 
-```python
-{
-    "image":       PIL.Image,   # full-page score render (LilyPond Emmentaler font)
-    "score_id":    str,         # e.g. "lc6583477"
-    "composer":    str,
-    "opus":        str,
-    "title":       str,
-    "corpus":      str,         # "lieder" or "quartets"
-    "instruments": list[str],
-    "page":        int,         # 1-indexed
-    "n_pages":     int,
-}
-```
+### `pages_transcribed` — image + per-page MusicXML (SFT-ready)
+
+Each row is one rendered page paired with the MusicXML for the bars on that
+page. Suitable for supervised fine-tuning of OMR models.
+
+| Split | Rows |
+|-------|-----:|
+| train | 14,129 |
+| test  |    455 |
+| dev   |    329 |
+
+Fields:
+
+| Field | Type | Description |
+|-------|------|-------------|
+| `image` | PIL.Image | Full-page score render |
+| `score_id` | str | Score identifier (e.g. `lc6583477`) |
+| `corpus` | str | `lieder`, `quartets`, or `orchestra` |
+| `composer` | str | |
+| `opus` | str | |
+| `title` | str | |
+| `page` | int | 1-indexed page number |
+| `n_pages` | int | Total pages in the score |
+| `bar_start` | int | First bar number on this page |
+| `bar_end` | int | Last bar number on this page (inclusive) |
+| `musicxml` | str | MusicXML for `bar_start`–`bar_end` |
+
+---
+
+### `pages` — image only, all corpora
+
+Same rows as `pages_transcribed` but without the `musicxml`, `bar_start`, and
+`bar_end` fields. Useful for unsupervised pre-training or image-only tasks.
+
+| Split | Rows |
+|-------|-----:|
+| train | 16,225 |
+| test  |    478 |
+| dev   |    339 |
+
+---
+
+### `scores` — full MusicXML per score
+
+One row per score (not per page). Contains the complete MusicXML for the
+entire piece plus metadata.
+
+| Split | Rows |
+|-------|-----:|
+| train | 1,424 |
+| test  |    79 |
+| dev   |    79 |
+
+Fields: `score_id`, `composer`, `opus`, `title`, `corpus`, `instruments`
+(list), `page` (total pages), `n_pages`, `musicxml` (full score).
+
+---
 
 ## Usage
 
+### Load `pages_transcribed`
+
 ```python
 from datasets import load_dataset
-ds = load_dataset("zzsi/openscore")
+
+ds = load_dataset("zzsi/openscore", "pages_transcribed")
 example = ds["train"][0]
 example["image"].show()
+print(example["musicxml"][:500])
+```
+
+### Filter by corpus (streaming)
+
+The dataset is sorted by `corpus` within each split, so row groups in the
+parquet files are corpus-homogeneous. This means streaming with a corpus
+filter is efficient: non-matching row groups are skipped without being
+downloaded.
+
+```python
+from datasets import load_dataset
+
+# Lieder only
+ds = load_dataset("zzsi/openscore", "pages_transcribed",
+                  streaming=True, split="train")
+ds = ds.filter(lambda r: r["corpus"] == "lieder")
+
+# Lieder + quartets (no orchestra)
+ds = ds.filter(lambda r: r["corpus"] in {"lieder", "quartets"})
+```
+
+### Quick subset for testing
+
+```python
+# First 100 rows (any corpus)
+ds = load_dataset("zzsi/openscore", "pages_transcribed",
+                  streaming=True, split="train")
+sample = list(ds.take(100))
+```
+
+### Fine-tuning example (Qwen-VL style)
+
+```python
+from datasets import load_dataset
+
+ds = load_dataset("zzsi/openscore", "pages_transcribed", split="train")
+
+def to_chat(row):
+    return {
+        "messages": [
+            {"role": "user", "content": [
+                {"type": "image", "image": row["image"]},
+                {"type": "text",  "text": "Transcribe this sheet music page to MusicXML."},
+            ]},
+            {"role": "assistant", "content": row["musicxml"]},
+        ]
+    }
+
+ds = ds.map(to_chat)
 ```
 
+---
+
+## Construction
+
+1. **Render**: Source MusicXML is converted to LilyPond (`.ly`) format and
+   rendered to SVG pages using a Docker image containing LilyPond 2.24.
+   Bar numbers are made visible on every bar (`all-bar-numbers-visible`).
+2. **Align**: Bar numbers are parsed from each SVG page to determine which
+   bars appear on each page.
+3. **Slice**: music21 slices the source MusicXML to the bar range for each
+   page and re-exports it as a self-contained MusicXML fragment.
+
+Pages whose bar numbers could not be reliably parsed (e.g. continuation
+pages with no bar number printed) are excluded.
+
+---
+
+## Known Limitations
+
+- **Pickup bars**: Scores with a pickup bar (anacrusis) have an implicit
+  measure 0 that is accounted for in `bar_start`/`bar_end`.
+- **Orchestra page alignment**: Orchestra scores frequently render to a
+  different page count than the original due to `\RemoveEmptyStaves` in
+  LilyPond. Alignment is based on bar numbers embedded in the rendered SVG,
+  not on page index.
+- **MusicXML slice quality**: Sliced MusicXML may be missing some cross-page
+  spanners (slurs, hairpins). Inexpressible rhythms (rare) cause individual
+  pages to be dropped.
+- **Render failures**: ~6% of lieder scores, 3% of quartet scores, and 2
+  orchestra movements failed to render and are absent from the dataset.
+
+---
+
 ## License
 
-Source scores: [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/)
-LilyPond renders: same license as source scores.
+Source scores are released under
+[CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/).
+LilyPond renders and derived MusicXML slices carry the same license.
+
+---
 
 ## Attribution
 
-- OpenScore Lieder corpus: https://github.com/OpenScore/Lieder
-- OpenScore String Quartets: https://github.com/OpenScore/StringQuartets
-- OpenScore Orchestra (Hauptstimme): https://github.com/MarkGotham/Hauptstimme
+- **OpenScore Lieder** — scores transcribed by the OpenScore community:
+  https://github.com/OpenScore/Lieder
+- **OpenScore String Quartets** — scores transcribed by the OpenScore community:
+  https://github.com/OpenScore/StringQuartets
+- **Hauptstimme (Orchestra)** — scores curated by Mark Gotham:
+  https://github.com/MarkGotham/Hauptstimme
+
+Rendering pipeline uses [LilyPond](https://lilypond.org) and
+[music21](https://web.mit.edu/music21/). Dataset construction code:
+https://github.com/zhudotexe/CVlization