YuE2-3B: open song generation that exposes the score as an interface
The open song generation model from m-a-p, 3B parameters, weights under CC-BY-NC-4.0, turning lyrics and a style prompt into a complete song with vocals and accompaniment at 48 kHz stereo. We list it as the open-weight top row for music in the audio domain on the strength of a combination that is close to unique among its peers: open weights plus an editable intermediate representation. One AR-NAR Mixture-of-Transformers backbone writes an ABC score (melody and chords) and semantic tokens, flow matching then produces acoustic latents and a VAE decodes them, so the score is an artefact that a person or an agent can read and edit instead of a black box whose only control is another sample. Three cot modes (full, melody, off) map onto composing, covering and direct generation, and the official agentic editing demo runs nine turns across fourteen versions from Mandarin pop to English jazz. Read the benchmark protocol carefully: on 192 WildSongBench prompts the best-of-8 SongBench average of 6.9632 sits above Suno v5 at 6.8721 and Suno v6 at 6.5562, but that is eight candidates with selection against a delivered single candidate; MuLan and AllMusicCaps, the two style-text alignment measures, still favour Suno v5, and PER at 8.44 percent trails Suno v6 Wild at 7.45 and MiniMax Music 3 at 6.27. Cost is the most concrete advantage: a 3.6 minute song in 71 seconds on an RTX 4090 24GB with a peak of 11.18 GiB, and 373 songs per hour on an H800 with vLLM at AR concurrency 32. Limits: non-commercial licence; identity preservation in covers comes almost entirely from a supplied score (CLEWS mAP collapses to 0.006 without one); the benchmark runs on the legacy VAE while the default release is the newer one; no technical report yet and no arena result. Graded C (vendor claim), not recomputed by us.