Simplify the following text for a Grade 9 native English-speaking person.
Original: In September 2002 , 60 years after conducting the Orchestra at the age of twelve at Lewisohn Stadium , Lorin Maazel became conductor of the Philharmonic .
Simplified: He assumed the post in September 2002 , 60 years after making his debut with the Orchestra at the age of twelve at Lewisohn Stadium .