Model Description
- Base model: Qwen/Qwen3-8B
- Model size: 8.2B
- Type: Causal Language Model
- Precision: bfloat16
Quick Start
Clone our GitHub code repo, run through the setup steps, and try:
git clone https://github.com/elianakim/Decomposer.git
cd Decomposer
uv sync
uv run generate_transformers.py \
--model haiyewon/Decomposer-Qwen3-8B \
--midi_path path/to/input.mid \
--n_outputs 5
The repo and inference scripts provide a more complete usage guide.
Model Details
MIDI is serialized as instrument-wise note events. Onsets are given in
cycle coordinates instead of seconds:
[BPM=120 Meter=4]
[acoustic_grand_piano] C4@0.00 E4@0.25 G4@0.50 C5@1.00
[drum] bass_drum@0.00 closed_hi_hat@0.25 closed_hi_hat@0.50 snare@0.75
- Header
[BPM=… Meter=…] — tempo/meter; if absent, madmom is used to estimate them.
- Events — one line per instrument,
pitch@cycle_onset tokens; melodic pitches as note
names (C4, F#3), drums as GM drum names (bass_drum, closed_hi_hat).
Training Data
Strudel-Synth is a synthetic corpus of 21,174 (MIDI, Strudel) pairs
(20,152 train / 1,022 test) built by distilling Strudel programs from Claude-Opus-4.6
and rendering each to MIDI with the Strudel runtime. Its ~20K training split is divided
into two disjoint ~10K halves, one per stage:
- SFT uses the first half as paired (MIDI, Strudel) examples.
- RL uses the second half (MIDI only), plus short-fragment (<30 s) LMD MIDI.
Inference Hyperparameters
Recommended settings matching the paper evaluation:
Table with columns: Setting, Value| Setting | Value |
|---|
temperature | 1.0 |
max_new_tokens | 4096 |
enable_thinking | false |
Citation
If you find our model useful, please cite our research as
@article{kim2026decomposer,
title = {Decomposer: Learning to Decompile Symbolic Music to Programs},
author = {Kim, Yewon and Gandhi, Apurva and Chung, David and Neubig, Graham and Donahue, Chris},
journal = {arXiv preprint arXiv:2607.01849},
year = {2026}
}