Complex sentence: Between 1908 and 1914, composer Claude Debussy began work on two one-act operas based on "The Devil in the Belfry" and "The Fall of the House of Usher" but only 30 minutes of "Usher" were completed before Debussy's death.
Split into simpler sentences: Between 1908 and 1914, composer Claude Debussy worked on two one-act operas, one based on "The Devil in the Belfry" and the other based on "The Fall of the House of Usher". However, only 30 minutes of "Usher" were completed before Debussy's death.