SongBloom: Coherent Song Generation via Interleaved Autoregressive Sketching and Diffusion Refinement

We propose SongBloom, a novel framework for full-length song generation that leverages an interleaved paradigm of autoregressive sketching and diffusion-based refinement. SongBloom employs an autoregressive diffusion model that combines the high fidelity of diffusion models with the scalability of language models. Specifically, it gradually extends a musical sketch from short to long and refines the details from coarse to fine-grained. The interleaved generation paradigm effectively integrates prior semantic and acoustic context to guide the generation process. Experimental results demonstrate that SongBloom outperforms existing methods across both subjective and objective metrics and achieves performance comparable to the state-of-the-art commercial music generation platforms.

Models

Updates

• Jun 2025: Release the songbloom_full_150s and inference script
• Sep 2025: Release the songbloom_full_150s model with DPO post-training

Getting Started

Prepare Environments

conda create -n SongBloom python==3.8.12
conda activate SongBloom

# yum install libsndfile
# pip install torch==2.2.0 torchaudio==2.2.0 --index-url https://download.pytorch.org/whl/cu118 # For different CUDA version
pip install -r requirements.txt

Data Preparation

A .jsonl file, where each line is a json object:

{
	"idx": "The index of each sample", 
	"lyrics": "The lyrics to be generated",
	"prompt_wav": "The path of the style prompt audio",
}

One example can be refered to as: example/test.jsonl

The prompt wav should be a 10-second, 48kHz audio clip.

For details on lyric formatting, see docs/lyric_format.md.

Inference

source set_env.sh

python3 infer.py --input-jsonl example/test.jsonl

# For GPUs with low VRAM like RTX4090, you should set the dtype as bfloat16
python3 infer.py --input-jsonl example/test.jsonl --dtype bfloat16

# SongBloom also supports flash-attn (optional). To enable it, please install flash-attn (v2.6.3 is used during training) manually and set os.environ['DISABLE_FLASH_ATTN'] = "0" in infer.py:8

Citation

@article{yang2025songbloom,
title={SongBloom: Coherent Song Generation via Interleaved Autoregressive Sketching and Diffusion Refinement},
author={Yang, Chenyu and Wang, Shuai and Chen, Hangting and Tan, Wei and Yu, Jianwei and Li, Haizhou},
journal={arXiv preprint arXiv:2506.07634},
year={2025}
}

License

SongBloom (codes and weights) is released under the Apache License 2.0.