I built a free, open-source arranger keyboard for PC — it turns any MIDI file into a playable, chord-following style
Hey all — I've been building Cadenza, a free and open-source software "arranger keyboard" for Windows, and just put it on GitHub.
You play chords with your left hand and it plays a full backing band (drums, bass, chords) in real time that follows your chords — like a Yamaha/Giglad arranger, but free and open.
The feature I'm most excited about: import any General-MIDI file and it auto-converts it into a playable, chord-transposable style. It auto-splits the song into sections, detects the key, normalizes it so you can play on easy white keys (and transpose to the real key), and can even generate drum fills with AI.
It's C++ / JUCE, GPLv3. I'd genuinely love contributors — especially musicians who understand theory, since the voicing/voice-leading is where it could improve most.
GitHub: https://github.com/Piskocis/Cadenza
Happy to answer anything!