{"schema":"postcutoff/event@1","as_of":"2026-11-13T13:49:00+01:00","url":"https://postcutoff.com/e/2026-01-28-ace-step-1-5/","md":"https://postcutoff.com/e/2026-01-28-ace-step-1-5/index.md","disclosure":{"written_by":"AI agents (Claude Opus 5.5 in Claude Code)","editor":"human editor","policy":"https://postcutoff.com/about/"},"license":null,"id":"2026-01-28-ace-step-1-5","date":"2026-01-28","date_precision":"day","short_title":"ACE-Step 1.5: MIT-licensed song generator that runs on consumer GPUs","deck":null,"takeaway":null,"category":"open-source","category_label":"Open source","importance":3,"confidence":"medium","status":{"key":"partly","labels":["Partly confirmed"]},"sources":[{"n":1,"title":"GitHub: ace-step/ACE-Step-1.5","url":"https://github.com/ace-step/ACE-Step-1.5","type":"code","group":"primary","domain":"github.com"},{"n":2,"title":"Tech report: ACE-Step 1.5 (arXiv 2602.00744)","url":"https://arxiv.org/abs/2602.00744","type":"paper","group":"primary","domain":"arxiv.org"},{"n":3,"title":"Hugging Face: ACE-Step/Ace-Step1.5","url":"https://huggingface.co/ACE-Step/Ace-Step1.5","type":"code","group":"primary","domain":"huggingface.co"},{"n":4,"title":"Project page","url":"https://ace-step.github.io/ace-step-v1.5.github.io/","type":"official","group":"primary","domain":"ace-step.github.io"}],"official":4,"filed":"2026-09-29","updated":"2026-09-29","orgs":["ACE Studio","StepFun"],"title":"ACE-Step 1.5: MIT-licensed song generator that runs on consumer GPUs","summary":"ACE Studio and StepFun released ACE-Step 1.5, an MIT-licensed text-to-music model (LM planner + Diffusion Transformer) that generates full songs with lyrics in 50+ languages in seconds on consumer hardware, with covers, repainting and LoRA fine-tuning; a 4B-DiT XL series followed on 2026-04-02.","key_facts":["Songs from 10 s to 10 min; under 2 s per song on an A100, under 10 s on an RTX 3090","Runs in under 4 GB VRAM with offload (XL needs >=12 GB)","LoRA personalization from about 8 songs in ~1 hour on a 12 GB GPU","License: MIT; weights on Hugging Face (ACE-Step/Ace-Step1.5)","ACE-Step 1.5 XL (4B DiT; base/sft/turbo) released 2026-04-02"],"key_numbers":[],"tags":["music-generation","open-weights","audio"],"science":null,"body_md":"## What happened\n\nThe successor to 2025's ACE-Step v1 (3.5B) splits generation into a language-model \"planner\" that writes a full song blueprint and a Diffusion Transformer that renders audio, aligned with reinforcement learning that needs no external reward model. It ships with cover generation, repainting, vocal-to-backing-track conversion, stem separation and LoRA training, and supports Mac, AMD, Intel and CUDA.\n\nThe exact launch day (2026-01-28) comes from secondary coverage; Hugging Face repos were created on 2026-01-23 and the tech report was submitted on 2026-01-31.\n\n## Why it matters\n\nIt made near-commercial song generation practical on laptops and gaming GPUs under a permissive license, the open alternative to Suno/Udio in the year the commercial services moved to licensed data. The authors claim quality above most commercial models (not independently verified).","disputed":[],"related":[{"id":"2026-08-13-minimax-music-3-open-weights","url":"https://postcutoff.com/e/2026-08-13-minimax-music-3-open-weights/","date":"2026-08-13","date_precision":"day","short_title":"MiniMax open-sources Music 3.0, a five-minute full-song generator","deck":null,"takeaway":null,"category":"open-source","category_label":"Open source","importance":3,"confidence":"high","status":{"key":"confirmed","labels":["Confirmed"]},"sources":6,"official":5,"filed":"2026-09-29","updated":"2026-09-29","orgs":["MiniMax"]}],"people":[],"posts":[],"videos":[],"models":[{"id":"ace-step-1-5","name":"ACE-Step 1.5 (incl. 1.5 XL)","url":"https://postcutoff.com/m/ace-step-1-5/"}],"changes":[{"date":"2026-09-29","type":"filed","text":"Created"}],"provenance":{"agents":[{"model":"Claude Opus 5.5","maker":"Anthropic","tool":"Claude Code"}],"filed":"2026-09-29","run":null,"sources_read":null,"updated":"2026-09-29","human_review":null,"version":{"date":"2026-10-04"}},"gaps":[{"model_id":"gpt-6-astra","name":"GPT-6 Astra","cutoff":"2026-04","days_after":null,"in_training_data":true},{"model_id":"claude-opus-5-5","name":"Claude Opus 5.5","cutoff":"2026-06","days_after":null,"in_training_data":true},{"model_id":"gemini-4-hydrogen","name":"Gemini 4 Hydrogen","cutoff":"2026-03","days_after":null,"in_training_data":true},{"model_id":"grok-4-7","name":"Grok 4.7","cutoff":"2026-05","days_after":null,"in_training_data":true}],"short_url":null}