Complex sentence: The location was used to film's finale, a graduation ceremony, where students perform "I Sing the Body Electric"; the sequence was filmed over the course of four days, and involved 400 extras, and 150 student musicians.
Split into simpler sentences: The location was used to shoot the film's finale, a graduation ceremony, where students perform the musical number "I Sing the Body Electric". The sequence was filmed over the course of four days, and involved 400 extras, and 150 student musicians.