Tools: Capo2keys : A Tool For Converting Guitar Chord Charts For Piano
Posted on Feb 19
• Originally published at reprodev.com
Well hello, it's been a hot minute since I've last posted on this blog but so much has gone on since my last post about Docker almost 2 years ago. I've not had as much free time but I've been busy working on a bunch of new articles and coding ideas.
Plus thanks to the almost daily advances of AI, it's meant that I can now tackle projects in a much more efficient and productive way. With that out of the way, here's a little something I vibe-coded while I was procrastinating over something else and wanted to see how AI would stack up as a coding partner.
I took up learning the piano towards the end of 2024 but have played guitar for much longer than that. I loved being able to pick up the guitar with a capo and play songs from Chord sheets on the internet. The main problem being that my music theory was not good enough to be able to easily transpose these to Piano especially when those chord sheets have lyrics.
I was able to get ChatGPT to transpose a lot of these by copying and pasting in the content that it converted and I would then convert these to a PDF manually. It was a tedious process that worked quite well until it didn't anymore.
As we got the end of November 2025, songs were failing due to errors that first didn't make sense as some worked and some didn't. This seemed to be combination of copyright issues with the song lyrics and that due to that sometimes ChatGPT would either choke, give me one verse or tell me that it wasn't designed to do this in an error message.
With that out of the way, here's a little something I vibe-coded while I was procrastinating over something else and wanted to see how AI would stack up as a coding partner.
Introducing Capo2Keys, a GUI tool built in Flask but deployed as a Docker container with Web UI to help convert and then export, guitar capo chord charts into piano-ready keys as a PDF and TXT file, all while preserving lyrics and chord structure.
Convert guitar capo chord charts into piano-ready keys while preserving lyrics and chord structure.
Capo2Keys provides a Docker-first Flask WebUI, a CLI mode for scripts, and an optional desktop app build from the same codebase.
Source: Dev.to
