Complex sentence: Pyotr Ilyich Tchaikovsky's earlier symphonies are generally optimistic works of nationalistic character, while the later symphonies are more intensely dramatic, particularly the Sixth, generally interpreted as a declaration of despair.
Split into simpler sentences: Pyotr Ilyich Tchaikovsky's earlier symphonies are generally optimistic works of nationalistic character. The later symphonies are more intensely dramatic, particularly the Sixth, generally interpreted as a declaration of despair.