This is true. I have come across other instances where the explanations are incorrect. The app is not ready for prime time, but fine-tuned models can improve this.
You don't need to fine tune GPT4 for it. A tiny in comparison model trained specifically on chords would do much better for creativity and the explanations could be generated without any AI.
There are lots of ways to solve this problem. Procedural, tiny model, fine-tuned large model, expert systems, etc.