Maybe do a quiz matching composers to their works because there is more than one famous composer for each country like Bizet for France or Rimsky-Korsakov for Russia, so it’s unclear who out of the many is the composer that is the answer.
I agree with admaioremdeietc. Clearly how "great" an artist is is a matter of opinion, unlike, say, a shot putter, whose performance can be measured. Germany has produced many great composers and nobody would deny that Bach was one of the greatest - but was he really greater than Beethoven? How do you decide? Also there is a typo in Tchaikovsky but in any case, I reckon that both Rachmaninov and Shostakovitch were greater.