it gave me a correct answer (but not the one GP expected), and then I asked it about another chord GP wanted it to say (D flat major) which can be stylistically replaced with this one (by "inverting" the top note). I asked it what the relationship between the two was and it told me about how they're used in songwriting correctly (gave information about the emotions they invoke and how they resolve to other chords), but didnt tell me the (frankly, trivia/irrelevant to songwriting) fact that they share notes if you happen to invert it in a particular way.

In music theory a set of the same notes can be one of several chords, the correct answer as to which one it is depends on the "key" of the song and context which wasnt provided, so the AI decided to define the root note of the chord as the bottom one which is a good and pretty standard assumption.

It's kind of like asking the AI about two equivalent mathematical functions expressed in different notation, and it saying a bunch of correct facts about the functions like their derivative, x intercept and stuff and how it can be used, but needing a prod to explicitly say the fact that they are interchangable. It's the kind of trivial barely-qualifies-as-an "oversight" I would expect actual human people who fully understand the material to make.