Open-Source Music Generation
A unified guide to two major open-source music generation ecosystems: HeartMuLa and AudioCraft (MusicGen/AudioGen). Both generate audio from text descriptions; HeartMuLa specializes in lyrics-conditioned song generation while AudioCraft offers broader text-to-music and text-to-sound capabilities with melody conditioning.
Quick Comparison
| Feature | HeartMuLa | AudioCraft |
|---|---|---|
| Focus | Lyrics+tags song generation | Text-to-music, text-to-sound |
| Model sizes | 3B, 7B | 300M (small) to 3.3B (large) |
| Output | MP3 48kHz stereo | WAV 32kHz mono/stereo |
| VRAM (min) | ~6.2GB (3B lazy) | ~2GB (small fp16) to ~16GB (large) |
| Lyrics support | Core feature (required) | Not supported (text-only) |
| Melody conditioning | No | Yes (musicgen-melody) |
| License | Apache-2.0 | MIT |
| Setup complexity | Medium (patches needed) | Low (pip install) |
When to use HeartMuLa: You need to generate a full song with lyrics, multiple languages, or want the most open-source-capable Suno alternative.
When to use AudioCraft: You need text-to-music or text-to-sound effects, melody conditioning, stereo output, or style transfer.
HeartMuLa — Lyrics-to-Song Generation
HeartMuLa generates full songs from lyrics + genre/style tags. Families of models: HeartMuLa (music language model), HeartCodec (12.5Hz audio codec), HeartTranscriptor (lyrics transcription), HeartCLAP (audio-text alignment).
Hardware Requirements
- Minimum: 8GB VRAM with
--lazy_load true(loads/unloads models sequentially, peaks ~6.2GB) - Recommended: 16GB+ VRAM for single-GPU
- Multi-GPU:
--mula_device cuda:0 --codec_device cuda:1 - CPU mode: Possible with
--mula_device cpu --codec_device cpubut extremely slow (30-60 min per song)
Installation
# 1. Clone
git clone https://github.com/HeartMuLa/heartlib.git
cd heartlib
# 2. Python 3.10 venv
uv venv --python 3.10 .venv
. .venv/bin/activate
uv pip install -e .
# 3. Fix dependency conflicts
uv pip install --upgrade datasets transformers
# 4. Download models (all in parallel)
hf download --local-dir './ckpt' 'HeartMuLa/HeartMuLaGen'
hf download --local-dir './ckpt/HeartMuLa-oss-3B' 'HeartMuLa/HeartMuLa-oss-3B-happy-new-year'
hf download --local-dir './ckpt/HeartCodec-oss' 'HeartMuLa/HeartCodec-oss-20260123'
Source Patches Required
Patch 1 — RoPE cache fix in src/heartlib/heartmula/modeling_heartmula.py:
Add RoPE reinitialization in setup_caches after reset_caches and before with device::
from torchtune.models.llama3_1._position_embeddings import Llama3ScaledRoPE
for module in self.modules():
if isinstance(module, Llama3ScaledRoPE) and not module.is_cache_built:
module.rope_init()
module.to(device)
Patch 2 — HeartCodec loading fix in src/heartlib/pipelines/music_generation.py:
Add ignore_mismatched_sizes=True to ALL HeartCodec.from_pretrained() calls.
Usage
cd heartlib && . .venv/bin/activate
python ./examples/run_music_generation.py \
--model_path=./ckpt \
--version="3B" \
--lyrics="./assets/lyrics.txt" \
--tags="./assets/tags.txt" \
--save_path="./assets/output.mp3" \
--lazy_load true
Tags (comma-separated, no spaces): piano,happy,wedding,synthesizer,romantic
Lyrics use bracketed structural tags: [Intro], [Verse], [Chorus], [Bridge], [Outro]
Key Parameters
| Parameter | Default | Description |
|---|---|---|
--max_audio_length_ms |
240000 | Max length (240s = 4 min) |
--temperature |
1.0 | Sampling temperature |
--cfg_scale |
1.5 | Classifier-free guidance scale |
--lazy_load |
false | Load/unload models on demand |
Pitfall: Do NOT use bf16 for HeartCodec — degrades audio quality. Use fp32.
Links
- Repo: https://github.com/HeartMuLa/heartlib
- Models: https://huggingface.co/HeartMuLa
- Paper: https://arxiv.org/abs/2601.10547
- License: Apache-2.0
AudioCraft — Text-to-Music and Text-to-Sound
Meta's AudioCraft framework covers MusicGen (text-to-music), AudioGen (text-to-sound), and EnCodec (neural audio codec).
Quick Start
pip install audiocraft
# Or for latest: pip install git+https://github.com/facebookresearch/audiocraft.git
Model Variants
| Model | Size | Use Case |
|---|---|---|
musicgen-small |
300M | Quick generation |
musicgen-medium |
1.5B | Balanced quality/speed |
musicgen-large |
3.3B | Best quality |
musicgen-melody |
1.5B | Melody-conditioned generation |
musicgen-stereo-medium |
1.5B | Stereo output |
musicgen-style |
1.5B | Style transfer from reference audio |
audiogen-medium |
1.5B | Sound effects generation |
Basic Text-to-Music
from audiocraft.models import MusicGen
import torchaudio
model = MusicGen.get_pretrained('facebook/musicgen-medium')
model.set_generation_params(duration=30, top_k=250, temperature=1.0, cfg_coef=3.0)
wav = model.generate(["upbeat electronic dance music with synths"])
torchaudio.save("output.wav", wav[0].cpu(), sample_rate=32000)
Text-to-Sound (AudioGen)
from audiocraft.models import AudioGen
model = AudioGen.get_pretrained('facebook/audiogen-medium')
model.set_generation_params(duration=5)
wav = model.generate(["dog barking in a park with birds chirping"])
torchaudio.save("sound.wav", wav[0].cpu(), sample_rate=16000)
Melody Conditioning
from audiocraft.models import MusicGen
model = MusicGen.get_pretrained('facebook/musicgen-melody')
model.set_generation_params(duration=30)
melody, sr = torchaudio.load("melody.wav")
wav = model.generate_with_chroma(["acoustic guitar folk song"], melody, sr)
Generation Parameters
| Parameter | Default | Description |
|---|---|---|
duration |
8.0 | Length in seconds (1-120) |
top_k |
250 | Top-k sampling |
top_p |
0.0 | Nucleus sampling |
temperature |
1.0 | Sampling temperature |
cfg_coef |
3.0 | Classifier-free guidance |
Performance
| Model | FP32 VRAM | FP16 VRAM | Generation Time (30s) |
|---|---|---|---|
| musicgen-small | ~4GB | ~2GB | ~5s |
| musicgen-medium | ~8GB | ~4GB | ~15s |
| musicgen-large | ~16GB | ~8GB | ~30s |
Advanced Usage
See references/audiocraft-advanced-usage.md for fine-tuning, MultiBand Diffusion, API server deployment, batch processing, LangChain integration, and evaluation.
Troubleshooting
See references/audiocraft-troubleshooting.md for common installation, model loading, generation, memory, and format issues.
Links
- GitHub: https://github.com/facebookresearch/audiocraft
- Paper (MusicGen): https://arxiv.org/abs/2306.05284
- Paper (AudioGen): https://arxiv.org/abs/2209.15352
- HuggingFace: https://huggingface.co/facebook/musicgen-small