Final answer:
Aaron Copland was 90 years old at the time of his death on December 2, 1990.
Step-by-step explanation:
Aaron Copland was an influential American composer known for his contribution to the world of music. However, the information provided seems to reference a different individual, Jackson Pollock, an American painter known for his role in the abstract expressionist movement. This indicates a mix-up in the information being used as a reference. To answer the question, Aaron Copland was born on November 14, 1900, and he passed away on December 2, 1990. This means that he was 90 years old when he died.