"What music is this?"
I feel that the problem here is with the English question. The question is too ambiguous. What music is this...is it referring to type (类型), nationality, artist-- there's no telling. This could lead to a variety of Chinese translations with different syntax, emphasizing something different. I'm thinking like 《这是什么音乐？》 (emphasizing manner/kind), and 《这音乐是什么？》 (generalized). Nearly the same thing, but Duo isn't accounting for them.