LeVo 2

LeVo 2: Hybrid LLM-Diffusion framework for stable full-length song generation with hierarchical modeling

LeVo 2 is a new hybrid LLM-Diffusion system for controllable full-length song generation that addresses the coherence-vs-acoustics trade-off through hierarchical token prediction: a language model handles semantic planning via mixed tokens, then predicts vocal and accompaniment tracks in parallel, while a diffusion-based codec reconstructs waveforms. A key contribution is an aesthetics-guided progressive post-training schedule combining SFT, offline DPO, and semi-online DPO to separately optimize quality, controllability, and musicality. Expert listening tests show LeVo 2 outperforms open-source baselines across six subjective dimensions and approaches leading commercial systems on several metrics.