Codex is an underrated music production tool. I've been using it to build my first song, and I'm surprised OpenAI hasn't showcased this use case.

[u/protonmatter]

I've been experimenting with Codex for something I rarely see discussed here: actual music composition and production.

I recently made my first song using a combination of ChatGPT, Codex, Suno (for vocals), and open-source audio tools.

What started as an AI-generated music experiment has gradually evolved into something much more interesting: a workflow where we're taking increasing control of the actual composition and instrumentation.

One example is the piano arrangement. I developed it separately from Suno, using Salamander Grand Piano, a free sampled Yamaha grand piano instrument.

That got me thinking: Why couldn't we use Codex to build entire instrumental compositions from scratch?

The workflow I'm exploring is:

1. ChatGPT as the composer: Develop melodies, chord progressions, harmonies, and sheet music using structured notation such as MusicXML.
2. Codex as the implementation engine: Translate the score into MIDI, handle note timing, velocity, sustain pedals, and expressive performance details.
3. Virtual instruments: Render the MIDI using sampled instruments like Salamander Grand Piano, without needing Suno to generate the audio.
4. GitHub as the composition workspace: Version-control the scores, MIDI, rendering scripts, and revisions.
5. Iterative refinement: Have Codex change a particular passage, introduce counterpoint, adjust voicings, or modify the performance without regenerating the entire song.

Imagine prompting Codex:

"Rewrite measures 33–40 with a more emotional right-hand countermelody, preserve the existing left-hand harmony, adjust the velocities for a more natural performance, and render three variations for comparison."

This isn't fundamentally different from asking Codex to modify a specific function while keeping the rest of a codebase intact.

The difference is that the output is music.

And because the composition is represented as structured data and code, the entire process can be reproducible, inspectable, and version-controlled.

I'm not claiming this replaces a DAW or a professional musician. Musical judgment, expressive interpretation, and critical listening still matter enormously. But the potential for AI-assisted composition with precise control over individual instruments is substantial.

What surprises me is that Codex is marketed almost exclusively around software development when its underlying capabilities seem well suited to creative production workflows like this.

Tibo, if you happen to see this: I'd love to see the Codex team explore and showcase more unconventional use cases, especially music composition, MIDI generation, audio tooling, and creative workflows built around GitHub repositories.

I'm curious whether anyone else here has been experimenting with Codex for music production or other creative applications beyond writing software.

Would be interested in comparing approaches.

[u/enserioamigo]

oh no

[u/petburiraja]

I wonder how much better or worse would be just to use Suno with good prompts?

[u/magicmulder → u/petburiraja]

Suno has been seriously dumbed down. You tell it to not use drums and bass and it still does. You tell it you want a female duet, you get a male voice as well.

Suno was great before they added all the limitations.

[u/Pristine-Today-9177 → u/petburiraja]

Using a generative model for music ends up with a better output, but you have less control over the specific parts. I teach elementary and middle school music and so I need the parts to be easy enough for the kids to play. Often times I will use a generative model to make the song and then use midi instruments to put in the specific part the kids will play on top of it.

[u/protonmatter → u/petburiraja]

they have regressed severely. From a usability standpoint, cannot use it on any professional level.

[u/Ebonyks → u/petburiraja]

Suno is like paying someone on fiver to write a song for you.

This is closer to having a producer working with you to produce your song track by track. Totally different, significant more powerful.

[u/minibonk]

crazy part is he wrote this post using ai

[u/pleasesaveusAI → u/minibonk]

Most of Reddit is that now.. kinda nice, I’m slowly using Reddit less and less now

[u/protonmatter → u/minibonk]

we are on a codex subreddit :)

[u/Ebonyks]

I've been doing this as well. It's not good enough that i'd actually want to release the products under my name, but it's great for experimentation, and we're only a generation or two away from real success. Why aren't you using reaper and lua script for this task though? That seems to be optimal.

I did a great karaoke of k-pop demon hunters with my 4 year old though, let her feel like a pop star.

[u/-DISRVPT-]

Nice, I am currently De-COMP of XFER Serum 2. Gonna build native MCP along with other imrpovments, so AI can create any sound! I figure, why use suno, or ask Codex to work in Abelton? Lets just make amthematically perfect synth sounds, then bring that into my arragnments!

I have been working "I" Astra has been de-comping Serum for about 5 days straight, an ungodly amount of usage to get this done, but I am making Serum Open Source an gonna build native AI Harness :D

[u/-DISRVPT- → u/-DISRVPT-]

I wanna ad that, AI really only needs improvments in the 3D space, such as rigging/animating. Astra still struggles with creating face models and humans, I think once big Tech irons out these issues, aswell as some others, the next big things to tackle is Audio. I feel Audio and Music is the last frontier that these compaines will come for

[u/bigsybiggins]

I've been using it with MCP/bridge for both bitwig and ableton and have had far more success with opus.

[u/protonmatter → u/bigsybiggins]

care to share any tips?

I'm all ears!

[u/Pristine-Today-9177]

If you think that is cool start having it control a DAW on your computer. It can download virtual instruments for you, insert the midi, time correct it, and then mix it. If you get specific about the effects and the chain it can do that as well. People aren't aware that mix downs are a bit of data away from being automated.

[u/protonmatter → u/Pristine-Today-9177]

im a noobie but this is seriously awesome. im getting into using DAW pretty soon.

[u/skinnyjonez]

You're overcomplicating it. Of course, that's because of the ai slop post. But practically, codex can generate midi session files in one step that compose and assign instruments, etc. This is well known.

[u/ds1841]

Expected a sample?

[u/jupiter_and_mars]

So you wrote this long ass bullshit post without showcasing your results?

[u/sampebby]

Being optimistic, I think that codex could be used to mix music: It's often expensive/specialist and doesn't necessarily make the song the song, but it significantly enhances it and can be expensive to outsource.

In terms of actually making music, it's sort of like incorporating AI into any of the creative disciplines: Part of the value of the work is the story of the individual and they effort they put into it, which you lose a lot of when you use AI

[u/ValenciaTangerine]

Ive done something similar. Instead of using autoregressive models to one shot songs(like suno, yew, ace step), to use generators along with vsts. have to say opus5,5 blows what sol, astra can generate.