As someone who has extensive knowledge of Finland, I can say that
Sibelius is the only composer even close to well-known outside of
Finland (and even among its own citizens), so the question starting
off with "This Finnish composer" in which the answer is not Sibelius
is inviting a neg. If I had been in a room with this question, I would
have been guaranteed a neg. If one wanted to write a question about
another Finnish composer outside of Sibelius probably should have
started the question with some other phrase. Just my two cents worth.