Music Fix

If you just rendered four minutes of instrumental from ACE-Step or pulled a Suno rip and it sounds fine but flat, this is the node you reach for. Music Fix is the "please just make it sound finished" button in jeankassio's ComfyUI Music Tools pack - and it's the rare automation that's honest about what it's doing. It applies a conservative mastering profile (subtle EQ, linked compression, stereo shaping, LUFS management, peak protection) and then gets out of your way.

The hook: two inputs, one output. You feed it AUDIO and pick a genre, and the node does the rest. That's the entire sales pitch, and for once the pitch mostly holds.

What the genre dropdown actually is

The genre input isn't a list of 18 presets - it's a dropdown of about 200 genre and subgenre labels, from "General / Balanced" through pop, rock, metal, hip-hop, electronic, classical, jazz, country, Latin, Brazilian, African, reggae, ambient, lo-fi, soundtrack, folk and experimental. Those 200 labels map down to 18 maintained DSP profiles, so "Brazilian / MPB" and "Brazilian / Samba" share a family profile. That's the right call: the profiles are a starting point, not a genre detector and not a guarantee of an artistic result.

The README is refreshingly blunt about the limits. EQ changes are deliberately subtle. Compression is linked so the stereo image doesn't pump. Bass widening is avoided (that's where "make it wider" goofs go to die). And when your requested LUFS target isn't safely reachable, the peak ceiling wins. Translation: this node will never make your mix louder than it can afford to be, and it will never embarrass you with an obvious EQ carve.

A real workflow

The pack's own suggested chain is the correct mental model:

Load Audio -> Audio Repair -> Noise Remove -> Music Fix -> Save Audio

Repair first, denoise second, then finish. Put Music Fix last - it's the finishing coat, and it assumes the audio underneath is already clean. For a TTS take or an AI-generated instrumental it's genuinely useful; for a professionally mixed track it'll mostly do nothing, which is also fine.

The gotcha people actually hit

People expect a genre profile to transform the sound toward that genre. It doesn't - and if you read the source, that's by design. The profile for "Classical / Romantic" nudges the three EQ bands, sets a compression ratio and a LUFS target; it can't conjure a string section out of a synth pad. If you want genre transformation, this is the wrong tool. If you want a tasteful, safe, loudness-correct finish in one node, it's the right one. Also worth knowing: the peak ceiling takes priority over the LUFS target, so on quiet source material the output may land below target loudness. That's the correct trade - you can always add gain after, you can't un-clip.

Install

Same as every node in this pack: ComfyUI Manager → search "ComfyUI Music Tools", or clone it into custom_nodes and pip install -r requirements.txt (numpy, scipy, pyloudnorm, noisereduce). Restart, and Music Fix appears under the music category. No model downloads, no GPU requirement - this is pure NumPy/SciPy DSP and runs near real-time on a potato.

The name oversells slightly - it's a finishing preset, not a magic fix-all. But as a genuinely good "last node before save" for generated audio, it earns its spot.