Is there something wrong with "did"? It is less pleasing English, but I think still acceptable?
I think Duolingo uses sentences 'backwards', as in this sentence that can be two ways in english but only one way in French but they only put in one of the options as correct.
I'm wondering what is meant by classical dance here. Ballet?
yes, "classical dance" is defined as "ballet" in one of the fill-in-the-blank conversations within the section in which the learner selects the correct phrase.