Show HN: Melogen – Generate MIDI melodies for free

[squirrelon]

Melogen generates short melodic phrases as .mid files, no rendered audio, just notes you drop into your DAW. Free to try, no signup required.

I built this because every "AI music" tool I'd tried produces finished audio, which is the opposite of what I want when I'm stuck on a hook. I wanted something that hands me a MIDI seed I can take into Ableton/FL/Logic and shape myself.

Under the hood: - Decoder-only transformer trained on MIDI - Outputs note sequences with timing and velocity - Tuned for short, usable phrases rather than full arrangements

It's still in beta and rough in places. I'd value blunt feedback on: - Whether the generations are actually musical, or just "notes that fit a key" - MIDI handling: timing, velocity, channel assignment - What's missing before it would slot into a real workflow

Happy to get into the model, dataset, or pipeline in the comments.

[squirrelon]

Feel free to comment any enhancement suggestions or points you have.

[Rochus]

Cool. Generation of symbolic music using transformers is indeed a pretty neglected field. I assume you have to encode more "musical knowledge" into the embeddings than when you "just" compress waveforms. Can you provide information on your embeddings?

[squirrelon]

Hi, It is actually not using transformers, those would be too slow. It is using a combination of CNN's and linear layers. Correct, it uses embedings, not waveforms or spectrograms. The inputs are midis, some of which I made myself in FL Studio. The model creates a "latent representation" from each midi, I can then sample randomly from this latent space to get an original piece. The most important part is the preprocessing in my opinion.

[Rochus]

That's fascinating. This sounds like a variational autoencoder. The embeddings, which from my humble point of view (as a trained musician) are a largely unexplored field not really supported by existing theory, are at the same time game-deciding. Have you found a good solution for this?