I am French, living in Germany. From my experiments with ChatGPT (I have access to GPT-4), the French is not going to be perfect, but so good that anyway nobody will ever notice the errors.

ChatGPT is a wonderful tool to improve your knowledge of a given language (at least for the ones having a lot of data on the web, I tested only French, German and English). You paste a mostly good text, you get back a very good one and sometimes it provides you with a description of your errors, why and what it restructured.

Would your question change if the tutor was a person? How do you know if anything anyone teaches you is correct?

It has been my experience that for things that may be slightly or very obscure, and/or controversial/uncertain, and/or with limited # of sources, and/or when pushed into complex dialogue or tricky questions, chatGPT can really muck things up.

At the same time, when asked simple, clear and basic questions, on topics where there are myriad of resources, that agree with each other, it's very very very useful.

I'm not learning either French nor Music theory solely from ChatGPT of course; I use it to supplement and explore. As such, it's proven to be in the top 5%+ of patient & knowledgeable tutors/instructors I've ever had (or to put it another way, my piano teachers have been WAY more wrong, WAY more often about music theory than ChatGPT - we all take risks :)

How do you know that the French and music theory that a human teacher would teach you is correct?