Input (grade 10): For example, 2 of Chopin's 52 mazurkas, and 1 of his nocturnes are in this key, though he seems to have preferred the related key C-sharp minor.
Output (grade 9): 2 of Chopin's 52 mazurkas, and 1 of his nocturnes are in this key, though he seems to have liked the related key C-sharp minor better.