Complex sentence: The decrepit Szpilman plays "Chopin's Ballade in G minor", which moves Hosenfeld enough to allow Szpilman to hide in the attic of the empty house where the German Captain regularly brings him food.
Split into simpler sentences: The decrepit Szpilman plays "Chopin's Ballade in G minor", which moves Hosenfeld. He allows Szpilman to hide in the attic of the empty house and regularly brings him food.