| --- |
| license: cc-by-4.0 |
| tags: |
| - guitar |
| - tablature |
| - fingering |
| - onnx |
| - music |
| library_name: onnx |
| --- |
| |
| # tab-labeler — symbolic guitar-tab fingering scorer (ONNX) |
|
|
| A tiny CNN that scores candidate **(string, fret)** placements for a sequence of |
| note-columns, so a guitar-tab **arranger** (Viterbi over hand positions) fingers |
| more like a human than a hand-tuned heuristic. The **symbolic arm** of a |
| two-model tab stack — the score/MIDI→tab counterpart to the audio→tab |
| [`cstr/tabcnn-onnx`](https://huggingface.co/cstr/tabcnn-onnx). It shares TabCNN's |
| exact per-string output contract, so the **same decoder** consumes both. |
|
|
| The model **never emits tab** — it only scores positions the arranger enumerated; |
| the arranger's transition cost + hard span cap stay the arbiter, so nothing |
| unplayable is produced. Missing → the heuristic is the fallback. |
|
|
| ## Versions |
|
|
| | file | training data | agreement | notes | |
| |---|---|---|---| |
| | `tab-labeler.onnx` (**default, v2**) | GuitarSet | 82.7% | shipped baseline | |
| | `tab-labeler-v1-lowmove.onnx` (v1) | GuitarSet | 78.59% | lower-movement fallback | |
| | `tab-labeler-v3-egset.onnx` (v3) | GuitarSet **+ EGSet12** | 82.5% (val 0.829) | more data; **better position** (6.23 vs human 6.20). GuitarSet-validated; OOD (IDMT) comparison pending | |
| | `tab-labeler-v3c-egset-spanreg.onnx` (v3c) | GuitarSet + EGSet12, span-regularized | val 0.829 | tighter emission (span-proxy 1.66); full benchmark pending | |
|
|
| Agreement = per-note (string,fret) match vs held-out human (GuitarSet player 05, |
| 60-song arranged benchmark). All models carry top-2 checkpoints (`.best.pt`). |
|
|
| ## ★ Integration: hitting span<1.5 at agreement>82% (no retraining) |
|
|
| **Quality is more than agreement.** Measured against the human on all axes |
| (GuitarSet, 60 songs; human = agreement 100% / movement 5325 / **span 1.43** / |
| position 6.20): |
|
|
| ``` |
| agreement movement span position |
| heuristic (no model) 57.0% 4095 1.34 4.93 (under-moves, under-reaches) |
| this model (mv=1.0) 82.7% 4372 1.68 6.43 (good move+pos; OVER-spans) |
| ``` |
|
|
| The model fingers at about the right position and moves about the right amount, |
| but picks **wider shapes than a human**. The fix is an **arranger-side knob**, |
| not a new model: because the arranger lets the model *replace* its local cost, |
| the span penalty is dropped — re-apply a span penalty **on top of** the emission |
| (`modelSpanCost` in CometBeat's `arrangeTab`). Sweep on v3 (GuitarSet): |
|
|
| | `modelSpanCost` | agreement | span | |
| |---|---|---| |
| | 0.00 | 82.5% | 1.77 | |
| | 0.20 | 83.5% | 1.59 | |
| | **0.50** | **84.0%** | **1.47** | |
|
|
| **Span and agreement are NOT a tradeoff — they align:** since the human fingers |
| compact (1.43), preferring compact shapes makes the model match the human *more*. |
| So `modelSpanCost≈0.5` gives **span 1.47 (<1.5) at agreement 84.0% (>82%)** with |
| movement still under the human — on any of these weights, no retraining. |
|
|
| ## IO contract |
|
|
| - **Input** `input : float32[N, 49, 9, 1]` — per column, a **9-column window** |
| (centred, zero-padded) of multi-hot **pitch-presence** over MIDI **40..88** |
| (49 bins). |
| - **Output** `output : float32[N, 6, 21]` — per-string **LogSoftmax** log-probs. |
| **class 0 = string silent**, **class k = fret k-1**. **String index 0 = high e** |
| … 5 = low E. Emission for `(string,fret)` = `output[string][fret+1]`. |
|
|
| ~338 k params, ~1.3 MB, opset 13. Conv / ReLU / MaxPool / Gemm / LogSoftmax — |
| runs on pure-Dart [`onnx_runtime_dart`](https://github.com/CrispStrobe/onnx_runtime_dart). |
|
|
| ## Training + evaluation |
|
|
| - **Data:** [GuitarSet](https://zenodo.org/records/3371780) (CC BY 4.0) — exact |
| `(pitch → string, fret)` labels; held out by guitarist (player 05 = val), |
| ±2-semitone transposition aug. **v3/v3c additionally use |
| [EGSet12](https://zenodo.org/records/11406378)** (CC BY 4.0, original electric |
| compositions — a 7th player). (A Guitar-TECHS-augmented variant, CC BY 4.0, was |
| trained too — val 0.823, slightly OOD; not published here.) |
| - **Objective:** sum of 6 per-string softmax cross-entropies (v3c adds a span |
| regularizer on the predicted distribution). |
|
|
| ## Provenance / license |
|
|
| **CC BY 4.0.** Derived weights redistributable **with attribution**. Trained on |
| GuitarSet (Xi et al., ISMIR 2018, CC BY 4.0); v3/v3c also on EGSet12 (CC BY 4.0). |
| No DadaGP / no request-gated data. |
|
|
| ## Provenance — authored here, and outside the GPAI definition |
|
|
| Added 2026-08-02 during an account-wide provenance review. |
|
|
| **These weights were trained by this repository's maintainer**, not converted |
| from someone else's model. Most `cstr/*` repositories are GGUF/ONNX conversions |
| where the upstream research team remains the provider; this one is not, and the |
| distinction matters because the two attract different obligations. The training |
| data, hyperparameters and licence inheritance are documented above. |
|
|
| **EU AI Act Art. 53 does not apply.** Art. 53 binds providers of *general-purpose |
| AI models*, which Art. 3(63) defines as models displaying "significant generality" |
| and capable of "competently performing a wide range of distinct tasks". A CNN scoring candidate (string, fret) placements for guitar tablature |
| is a narrow, single-task model and does not meet that definition, so the |
| Art. 53(1)(c) copyright-policy and 53(1)(d) training-content duties are not |
| engaged. This is recorded explicitly because "trained here" and "subject to |
| Art. 53" are easy to conflate, and only the first is true. |
|
|
| The training-data documentation above is published because it is useful and |
| because the licence inheritance depends on it — not because Art. 53 compels it. |
|
|
