Re:Show HN: Chipmunkify – I used ML to solve audio's dumbest...
by treelover on Sunday April 12, 2026 @11:42PM
(#47747313)
You know those YouTube channels with millions of views that are just popular songs, but chipmunk? They sound awful because they pitch-shift the entire track.
I fixed it.
The pipeline: Upload an MP3 -> Demucs isolates the vocals -> Rubber Band pitch-shifts them into the rodent register -> FFmpeg glues it back together. Hosted on Modal.
Guardrails protecting my $5/month Modal budget and net worth:
* 10MB max upload
* First 30 seconds only (Demucs is computationally brutal)
* 3 requests/IP/day
I delete your files immediately: not out of principle, but because I genuinely cannot afford to store them.
If the site throws an error, you've assassinated my budget and I will pour one out.
Try it out and let me know what you think. I suggest using a song that you love!
I fixed it.
The pipeline: Upload an MP3 -> Demucs isolates the vocals -> Rubber Band pitch-shifts them into the rodent register -> FFmpeg glues it back together. Hosted on Modal.
Guardrails protecting my $5/month Modal budget and net worth:
* 10MB max upload * First 30 seconds only (Demucs is computationally brutal) * 3 requests/IP/day
I delete your files immediately: not out of principle, but because I genuinely cannot afford to store them.
If the site throws an error, you've assassinated my budget and I will pour one out.
Try it out and let me know what you think. I suggest using a song that you love!